feat: Zod AI validation, AIProvenance governance, fix tests (154 green)

- Add AIProvenance + AIResponse<T> to IAIService — all 11 methods now
  return structured provenance (provider, model, source, fallbackUsed,
  validationPassed) instead of bare ItemResponse<T>
- Add schemas.ts with Zod schemas for all 8 AI response types;
  validateAIResponse() utility returns null on failure, never throws
- Rewrite OpenRouterAIService: every method validates AI JSON against
  its Zod schema; failed validation triggers MockAIService fallback
  with fallbackUsed:true — no invalid data can reach the UI
- Fix MockAIService.generateFollowUpQuestions: replace broken
  mockParseNeed(JSON.stringify(criteria)) with direct ParsedNeedCriteria
  field inspection; returns max 3 prioritised FollowUpQuestion objects
- Add provenance: mockProvenance() to all MockAIService responses
- Improve decisionBriefPrompt: structured JSON schema example,
  confidence vocabulary, availability disclaimer
- Improve matchExplanationPrompt: score-tier vocabulary, isFutureSignal
  flag forbids confirmed-availability language for future signals
- Add 102 new tests: mustHaveScorer (16), softFactorEnrichment (38),
  aiSchemas (52) — 154 total, all passing; 0 TypeScript errors

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/services/ai/IAIService.ts

@@ -1,8 +1,52 @@
-import type { ItemResponse } from '../types'
 import type { CreateNeedInput } from '../../domain/need'
 import type { ParseNeedResult, ParsedNeedCriteria, FollowUpQuestion } from '../../domain/needBuilder'
 import type { UnifiedMatchResult } from '../../domain/unifiedResult'
 
+// ── AI Provenance ─────────────────────────────────────────────────────────────
+// Attached to every AI response so the UI can always trace where data came from.
+
+export interface AIProvenance {
+  /** Which AI provider produced this response */
+  provider: 'openrouter' | 'mock'
+  /** Exact model ID (e.g. 'anthropic/claude-3-5-haiku') or 'mock' */
+  model: string
+  /** ISO-8601 timestamp of generation */
+  generatedAt: string
+  /** Prompt version string used to generate this response */
+  promptVersion: string
+  /** Whether the response is AI-only, mock-only, or a hybrid merge */
+  source: 'ai' | 'mock' | 'hybrid'
+  /** True when the original AI call failed and mock was substituted */
+  fallbackUsed: boolean
+  /** True when the AI response passed Zod schema validation */
+  validationPassed: boolean
+}
+
+/**
+ * All AI service methods return AIResponse<T> instead of ItemResponse<T>.
+ * `data` is backward-compatible — existing call sites using `result.data.xxx`
+ * continue to work unchanged.
+ */
+export type AIResponse<T> = {
+  data: T
+  provenance: AIProvenance
+}
+
+// ── Helper ────────────────────────────────────────────────────────────────────
+
+export function mockProvenance(overrides?: Partial<AIProvenance>): AIProvenance {
+  return {
+    provider: 'mock',
+    model: 'mock',
+    generatedAt: new Date().toISOString(),
+    promptVersion: 'mock',
+    source: 'mock',
+    fallbackUsed: false,
+    validationPassed: true,
+    ...overrides,
+  }
+}
+
 // ── Response Types ────────────────────────────────────────────────────────────
 
 export interface DecisionBrief {
@@ -49,8 +93,6 @@ export interface ParsedListingData {
   fitOut?: string
 }
 
-// ── New Response Types ────────────────────────────────────────────────────────
-
 export interface MatchExplanation {
   headline: string
   summary: string
@@ -124,29 +166,29 @@ export interface AIServiceProvider {
 
 export interface IAIService {
   // Need parsing (F008)
-  parseNeed(input: string): Promise<ItemResponse<ParseNeedResult>>
-  generateFollowUpQuestions(criteria: ParsedNeedCriteria): Promise<ItemResponse<FollowUpQuestion[]>>
+  parseNeed(input: string): Promise<AIResponse<ParseNeedResult>>
+  generateFollowUpQuestions(criteria: ParsedNeedCriteria): Promise<AIResponse<FollowUpQuestion[]>>
 
   // Match explainability (F004)
-  generateMatchExplanation(input: MatchExplanationInput): Promise<ItemResponse<MatchExplanation>>
-  summarizeTradeOffs(tradeoffs: TradeOffInput[]): Promise<ItemResponse<TradeOffSummary>>
+  generateMatchExplanation(input: MatchExplanationInput): Promise<AIResponse<MatchExplanation>>
+  summarizeTradeOffs(tradeoffs: TradeOffInput[]): Promise<AIResponse<TradeOffSummary>>
 
   // Compare (F014)
-  summarizeComparison(items: UnifiedMatchResult[]): Promise<ItemResponse<ComparisonSummary>>
+  summarizeComparison(items: UnifiedMatchResult[]): Promise<AIResponse<ComparisonSummary>>
 
   // Shortlist decision brief
-  generateDecisionBrief(shortlistId: string): Promise<ItemResponse<DecisionBrief>>
+  generateDecisionBrief(shortlistId: string): Promise<AIResponse<DecisionBrief>>
 
   // Data quality
-  generateDataQualitySummary(propertyId: string, quality: DataQualityInput): Promise<ItemResponse<DataQualitySummary>>
+  generateDataQualitySummary(propertyId: string, quality: DataQualityInput): Promise<AIResponse<DataQualitySummary>>
 
   // Market signal classification (OPERATIONS)
-  classifyMarketSignal(signalText: string): Promise<ItemResponse<MarketSignalClassification>>
+  classifyMarketSignal(signalText: string): Promise<AIResponse<MarketSignalClassification>>
 
   // Offer email (supply side)
-  generateOfferEmail(payload: OfferEmailPayload): Promise<ItemResponse<{ subject: string; body: string }>>
+  generateOfferEmail(payload: OfferEmailPayload): Promise<AIResponse<{ subject: string; body: string }>>
 
   // Legacy methods
-  extractCriteria(input: string): Promise<ItemResponse<CriteriaExtractionResult>>
-  generateFollowUp(partialNeed: Partial<CreateNeedInput>): Promise<ItemResponse<string[]>>
+  extractCriteria(input: string): Promise<AIResponse<CriteriaExtractionResult>>
+  generateFollowUp(partialNeed: Partial<CreateNeedInput>): Promise<AIResponse<string[]>>
 }

src/services/ai/__tests__/aiSchemas.test.ts

@@ -0,0 +1,345 @@
+import { describe, it, expect } from 'vitest'
+import {
+  NeedParsingResponseSchema,
+  FollowUpQuestionsResponseSchema,
+  TradeOffSummaryResponseSchema,
+  CompareSummaryResponseSchema,
+  DecisionBriefResponseSchema,
+  DataQualitySummaryResponseSchema,
+  MarketSignalClassificationResponseSchema,
+  OfferEmailResponseSchema,
+  ProbabilitySchema,
+  validateAIResponse,
+} from '../schemas'
+
+// ── ProbabilitySchema ─────────────────────────────────────────────────────────
+
+describe('ProbabilitySchema', () => {
+  it('accepts 0', () => expect(ProbabilitySchema.safeParse(0).success).toBe(true))
+  it('accepts 1', () => expect(ProbabilitySchema.safeParse(1).success).toBe(true))
+  it('accepts 0.65', () => expect(ProbabilitySchema.safeParse(0.65).success).toBe(true))
+  it('rejects -5', () => expect(ProbabilitySchema.safeParse(-5).success).toBe(false))
+  it('rejects 1.5', () => expect(ProbabilitySchema.safeParse(1.5).success).toBe(false))
+  it('rejects NaN', () => expect(ProbabilitySchema.safeParse(NaN).success).toBe(false))
+})
+
+// ── NeedParsingResponseSchema ─────────────────────────────────────────────────
+
+describe('NeedParsingResponseSchema', () => {
+  it('accepts a complete valid response', () => {
+    const result = NeedParsingResponseSchema.safeParse({
+      assetType: 'OFFICE',
+      areaRange: { min: 200, max: 500 },
+      preferredLocations: ['Zürich', 'Basel'],
+      budgetRange: { maxPerSqm: 45, currency: 'CHF' },
+      timing: { earliestMoveIn: '2025-01-01', flexibleTiming: false },
+      mustHaveCriteria: ['Erdgeschoss'],
+      missingFields: [],
+      assumptions: ['Fläche geschätzt'],
+    })
+    expect(result.success).toBe(true)
+  })
+
+  it('accepts a minimal response (all fields optional)', () => {
+    const result = NeedParsingResponseSchema.safeParse({})
+    expect(result.success).toBe(true)
+  })
+
+  it('accepts null for nullable fields', () => {
+    const result = NeedParsingResponseSchema.safeParse({ assetType: null, areaRange: null })
+    expect(result.success).toBe(true)
+  })
+
+  it('rejects areaRange where max < min', () => {
+    const result = NeedParsingResponseSchema.safeParse({
+      areaRange: { min: 500, max: 200 },
+    })
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects unknown assetType value', () => {
+    const result = NeedParsingResponseSchema.safeParse({ assetType: 'WAREHOUSE' })
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects negative area values', () => {
+    const result = NeedParsingResponseSchema.safeParse({ areaRange: { min: -10, max: 500 } })
+    expect(result.success).toBe(false)
+  })
+})
+
+// ── FollowUpQuestionsResponseSchema ───────────────────────────────────────────
+
+describe('FollowUpQuestionsResponseSchema', () => {
+  const validQuestion = {
+    questionText: 'Welchen Nutzungstyp suchen Sie?',
+    targetField: 'assetType',
+    reason: 'Pflichtfeld fehlt',
+    importance: 'required',
+  }
+
+  it('accepts valid question array', () => {
+    const result = FollowUpQuestionsResponseSchema.safeParse([validQuestion])
+    expect(result.success).toBe(true)
+  })
+
+  it('accepts empty array', () => {
+    const result = FollowUpQuestionsResponseSchema.safeParse([])
+    expect(result.success).toBe(true)
+  })
+
+  it('rejects array with more than 5 items', () => {
+    const questions = Array(6).fill(validQuestion)
+    const result = FollowUpQuestionsResponseSchema.safeParse(questions)
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects question with empty questionText', () => {
+    const result = FollowUpQuestionsResponseSchema.safeParse([{ ...validQuestion, questionText: '' }])
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects unknown importance value', () => {
+    const result = FollowUpQuestionsResponseSchema.safeParse([{ ...validQuestion, importance: 'critical' }])
+    expect(result.success).toBe(false)
+  })
+})
+
+// ── TradeOffSummaryResponseSchema ─────────────────────────────────────────────
+
+describe('TradeOffSummaryResponseSchema', () => {
+  const valid = {
+    headline: 'Hohe Mietkosten',
+    items: [{ concern: 'Budget überschritten', severity: 'HIGH', mitigation: 'Verhandlung möglich' }],
+    overallRisk: 'HIGH',
+  }
+
+  it('accepts valid trade-off summary', () => {
+    expect(TradeOffSummaryResponseSchema.safeParse(valid).success).toBe(true)
+  })
+
+  it('rejects unknown severity value', () => {
+    const bad = { ...valid, items: [{ concern: 'test', severity: 'CRITICAL' }] }
+    expect(TradeOffSummaryResponseSchema.safeParse(bad).success).toBe(false)
+  })
+
+  it('rejects unknown overallRisk value', () => {
+    const bad = { ...valid, overallRisk: 'EXTREME' }
+    expect(TradeOffSummaryResponseSchema.safeParse(bad).success).toBe(false)
+  })
+
+  it('rejects more than 5 items', () => {
+    const bad = { ...valid, items: Array(6).fill({ concern: 'x', severity: 'LOW' }) }
+    expect(TradeOffSummaryResponseSchema.safeParse(bad).success).toBe(false)
+  })
+
+  it('rejects missing headline', () => {
+    const { headline: _, ...bad } = valid
+    expect(TradeOffSummaryResponseSchema.safeParse(bad).success).toBe(false)
+  })
+})
+
+// ── CompareSummaryResponseSchema ──────────────────────────────────────────────
+
+describe('CompareSummaryResponseSchema', () => {
+  it('accepts valid compare summary', () => {
+    const result = CompareSummaryResponseSchema.safeParse({
+      overallAssessment: 'Objekt A ist am besten geeignet.',
+      recommendation: 'Besichtigungstermin für Objekt A vereinbaren.',
+      strongestOption: 'Objekt A',
+    })
+    expect(result.success).toBe(true)
+  })
+
+  it('accepts response with only overallAssessment (others optional)', () => {
+    const result = CompareSummaryResponseSchema.safeParse({ overallAssessment: 'Gute Optionen.' })
+    expect(result.success).toBe(true)
+  })
+
+  it('rejects empty overallAssessment', () => {
+    const result = CompareSummaryResponseSchema.safeParse({ overallAssessment: '' })
+    expect(result.success).toBe(false)
+  })
+})
+
+// ── DecisionBriefResponseSchema ───────────────────────────────────────────────
+
+describe('DecisionBriefResponseSchema', () => {
+  const validSection = { title: 'Zusammenfassung', body: 'Überblick über die Situation.' }
+
+  it('accepts valid decision brief', () => {
+    const result = DecisionBriefResponseSchema.safeParse({
+      summary: 'Executive Summary.',
+      sections: [validSection, { title: 'Empfehlung', body: 'Objekt A priorisieren.' }],
+    })
+    expect(result.success).toBe(true)
+  })
+
+  it('rejects missing sections', () => {
+    const result = DecisionBriefResponseSchema.safeParse({ summary: 'OK' })
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects empty sections array', () => {
+    const result = DecisionBriefResponseSchema.safeParse({ summary: 'OK', sections: [] })
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects more than 6 sections', () => {
+    const result = DecisionBriefResponseSchema.safeParse({
+      summary: 'OK',
+      sections: Array(7).fill(validSection),
+    })
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects section with empty body', () => {
+    const result = DecisionBriefResponseSchema.safeParse({
+      summary: 'OK',
+      sections: [{ title: 'Test', body: '' }],
+    })
+    expect(result.success).toBe(false)
+  })
+})
+
+// ── DataQualitySummaryResponseSchema ──────────────────────────────────────────
+
+describe('DataQualitySummaryResponseSchema', () => {
+  it('accepts valid data quality summary', () => {
+    const result = DataQualitySummaryResponseSchema.safeParse({
+      overallAssessment: 'Gute Datenqualität.',
+      missingCriticalFields: ['areaSqm'],
+      recommendation: 'Fläche ergänzen.',
+      confidence: 0.75,
+    })
+    expect(result.success).toBe(true)
+  })
+
+  it('rejects confidence > 1', () => {
+    const result = DataQualitySummaryResponseSchema.safeParse({
+      overallAssessment: 'Test',
+      recommendation: 'Test',
+      confidence: 1.5,
+    })
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects confidence < 0', () => {
+    const result = DataQualitySummaryResponseSchema.safeParse({
+      overallAssessment: 'Test',
+      recommendation: 'Test',
+      confidence: -0.1,
+    })
+    expect(result.success).toBe(false)
+  })
+})
+
+// ── MarketSignalClassificationResponseSchema ──────────────────────────────────
+
+describe('MarketSignalClassificationResponseSchema', () => {
+  const valid = {
+    signalType: 'VACANCY',
+    probability: 0.75,
+    timeHorizonMonths: 6,
+    areaSqmEstimate: 1200,
+    credibility: 'HIGH',
+    reasoning: 'Kündigung bekannt.',
+  }
+
+  it('accepts valid market signal', () => {
+    expect(MarketSignalClassificationResponseSchema.safeParse(valid).success).toBe(true)
+  })
+
+  it('accepts null for nullable optional fields', () => {
+    const result = MarketSignalClassificationResponseSchema.safeParse({
+      ...valid,
+      timeHorizonMonths: null,
+      areaSqmEstimate: null,
+    })
+    expect(result.success).toBe(true)
+  })
+
+  it('rejects probability -5', () => {
+    expect(MarketSignalClassificationResponseSchema.safeParse({ ...valid, probability: -5 }).success).toBe(false)
+  })
+
+  it('rejects probability 1.5', () => {
+    expect(MarketSignalClassificationResponseSchema.safeParse({ ...valid, probability: 1.5 }).success).toBe(false)
+  })
+
+  it('rejects unknown signalType', () => {
+    expect(MarketSignalClassificationResponseSchema.safeParse({ ...valid, signalType: 'FIRE_SALE' }).success).toBe(false)
+  })
+
+  it('rejects unknown credibility value', () => {
+    expect(MarketSignalClassificationResponseSchema.safeParse({ ...valid, credibility: 'VERY_HIGH' }).success).toBe(false)
+  })
+
+  it('rejects missing reasoning', () => {
+    const { reasoning: _, ...bad } = valid
+    expect(MarketSignalClassificationResponseSchema.safeParse(bad).success).toBe(false)
+  })
+
+  it('rejects non-integer timeHorizonMonths', () => {
+    expect(MarketSignalClassificationResponseSchema.safeParse({ ...valid, timeHorizonMonths: 2.5 }).success).toBe(false)
+  })
+})
+
+// ── OfferEmailResponseSchema ──────────────────────────────────────────────────
+
+describe('OfferEmailResponseSchema', () => {
+  it('accepts valid offer email', () => {
+    const result = OfferEmailResponseSchema.safeParse({
+      subject: 'Angebot Büroflächen',
+      body: 'Sehr geehrte Damen und Herren, wir bieten folgende Objekte an.',
+    })
+    expect(result.success).toBe(true)
+  })
+
+  it('rejects empty subject', () => {
+    const result = OfferEmailResponseSchema.safeParse({ subject: '', body: 'Valid body text here.' })
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects body shorter than 10 characters', () => {
+    const result = OfferEmailResponseSchema.safeParse({ subject: 'Angebot', body: 'Kurz.' })
+    expect(result.success).toBe(false)
+  })
+})
+
+// ── validateAIResponse helper ─────────────────────────────────────────────────
+
+describe('validateAIResponse helper', () => {
+  it('returns parsed data when schema passes', () => {
+    const result = validateAIResponse(
+      OfferEmailResponseSchema,
+      { subject: 'Test', body: 'Long enough body text here.' },
+      'test',
+    )
+    expect(result).not.toBeNull()
+    expect(result?.subject).toBe('Test')
+  })
+
+  it('returns null when schema fails (does not throw)', () => {
+    const result = validateAIResponse(
+      OfferEmailResponseSchema,
+      { subject: '', body: 'x' },
+      'test',
+    )
+    expect(result).toBeNull()
+  })
+
+  it('returns null for completely wrong shape (does not throw)', () => {
+    const result = validateAIResponse(
+      MarketSignalClassificationResponseSchema,
+      { probability: -999, signalType: 'INVALID' },
+      'test',
+    )
+    expect(result).toBeNull()
+  })
+
+  it('returns null for null input (does not throw)', () => {
+    const result = validateAIResponse(OfferEmailResponseSchema, null, 'test')
+    expect(result).toBeNull()
+  })
+})

src/services/ai/mock/MockAIService.ts

@@ -1,9 +1,9 @@
-import type { ItemResponse } from '../../types'
 import type { CreateNeedInput } from '../../../domain/need'
 import type { ParsedNeedCriteria, FollowUpQuestion } from '../../../domain/needBuilder'
 import type { UnifiedMatchResult } from '../../../domain/unifiedResult'
 import type {
   IAIService,
+  AIResponse,
   DecisionBrief,
   ComparisonSummary,
   CriteriaExtractionResult,
@@ -16,6 +16,7 @@ import type {
   DataQualitySummary,
   MarketSignalClassification,
 } from '../IAIService'
+import { mockProvenance } from '../IAIService'
 import { mockParseNeed } from './needParser'
 import { buildComparisonSummary } from './compareBuilder'
 import { buildMockDecisionBrief } from './decisionBrief'
@@ -23,19 +24,92 @@ import { buildMockDecisionBrief } from './decisionBrief'
 const SIMULATED_DELAY = { fast: 300, medium: 600, slow: 1800 }
 const delay = (ms: number) => new Promise(r => setTimeout(r, ms))
 
+// ── Follow-up question templates keyed by ParsedNeedCriteria field ────────────
+
+interface QuestionTemplate {
+  questionText: string
+  reason: string
+  suggestedAnswerOptions?: string[]
+  importance: FollowUpQuestion['importance']
+}
+
+const FOLLOW_UP_TEMPLATES: Partial<Record<keyof ParsedNeedCriteria, QuestionTemplate>> = {
+  assetType: {
+    questionText: 'Welchen Nutzungstyp suchen Sie?',
+    reason: 'Nutzungstyp ist zwingend für die Matchsuche',
+    suggestedAnswerOptions: ['Büro', 'Retail', 'Logistik', 'Produktion', 'Gastro'],
+    importance: 'required',
+  },
+  areaRange: {
+    questionText: 'Welche Fläche benötigen Sie (min–max in m²)?',
+    reason: 'Flächenbedarf ist zwingend für die Filterung',
+    importance: 'required',
+  },
+  preferredLocations: {
+    questionText: 'In welchen Städten oder Regionen suchen Sie?',
+    reason: 'Standortpräferenz fehlt',
+    suggestedAnswerOptions: ['Zürich', 'Basel', 'Bern', 'Zug', 'Genf', 'Lausanne'],
+    importance: 'required',
+  },
+  budgetRange: {
+    questionText: 'Was ist Ihr maximales Budget pro m² und Monat (CHF)?',
+    reason: 'Budget ist wichtig für die Filterung unpassender Objekte',
+    importance: 'recommended',
+  },
+  timing: {
+    questionText: 'Wann möchten Sie spätestens einziehen?',
+    reason: 'Verfügbarkeitstermin fehlt',
+    importance: 'recommended',
+  },
+  mustHaveCriteria: {
+    questionText: 'Haben Sie zwingende Anforderungen (ÖV-Anbindung, Parkplätze, Laderampe)?',
+    reason: 'Pflichtkriterien sind für die Filterung relevant',
+    importance: 'optional',
+  },
+}
+
+function buildFollowUpQuestions(criteria: ParsedNeedCriteria): FollowUpQuestion[] {
+  const missing: Array<keyof ParsedNeedCriteria> = []
+
+  if (!criteria.assetType)                          missing.push('assetType')
+  if (!criteria.areaRange)                          missing.push('areaRange')
+  if (!criteria.preferredLocations?.length)         missing.push('preferredLocations')
+  if (!criteria.budgetRange)                        missing.push('budgetRange')
+  if (!criteria.timing)                             missing.push('timing')
+  if (!criteria.mustHaveCriteria?.length)           missing.push('mustHaveCriteria')
+
+  return missing
+    .slice(0, 3)
+    .map((field, i) => {
+      const tpl = FOLLOW_UP_TEMPLATES[field]
+      if (!tpl) return null
+      const q: FollowUpQuestion = {
+        id:                     `fq-mock-${i}`,
+        questionText:           tpl.questionText,
+        targetField:            field,
+        reason:                 tpl.reason,
+        importance:             tpl.importance,
+        suggestedAnswerOptions: tpl.suggestedAnswerOptions,
+      }
+      return q
+    })
+    .filter((q): q is FollowUpQuestion => q !== null)
+}
+
+// ── Service ───────────────────────────────────────────────────────────────────
+
 export const MockAIService: IAIService = {
-  async parseNeed(input: string): Promise<ItemResponse<ReturnType<typeof mockParseNeed>>> {
+  async parseNeed(input: string): Promise<AIResponse<ReturnType<typeof mockParseNeed>>> {
     await delay(SIMULATED_DELAY.fast)
-    return { data: mockParseNeed(input) }
+    return { data: mockParseNeed(input), provenance: mockProvenance() }
   },
 
-  async generateFollowUpQuestions(criteria: ParsedNeedCriteria): Promise<ItemResponse<FollowUpQuestion[]>> {
+  async generateFollowUpQuestions(criteria: ParsedNeedCriteria): Promise<AIResponse<FollowUpQuestion[]>> {
     await delay(SIMULATED_DELAY.medium)
-    const result = mockParseNeed(JSON.stringify(criteria))
-    return { data: result.followUpQuestionCandidates }
+    return { data: buildFollowUpQuestions(criteria), provenance: mockProvenance() }
   },
 
-  async generateMatchExplanation(input: MatchExplanationInput): Promise<ItemResponse<MatchExplanation>> {
+  async generateMatchExplanation(input: MatchExplanationInput): Promise<AIResponse<MatchExplanation>> {
     await delay(SIMULATED_DELAY.medium)
     const isStrong = input.matchScore >= 78
     const isMedium = input.matchScore >= 52
@@ -56,10 +130,11 @@ export const MockAIService: IAIService = {
           ...input.negativeFactors.slice(0, 1).map(f => `− ${f.explanation}`),
         ],
       },
+      provenance: mockProvenance(),
     }
   },
 
-  async summarizeTradeOffs(tradeoffs: TradeOffInput[]): Promise<ItemResponse<TradeOffSummary>> {
+  async summarizeTradeOffs(tradeoffs: TradeOffInput[]): Promise<AIResponse<TradeOffSummary>> {
     await delay(SIMULATED_DELAY.fast)
     const critical = tradeoffs.filter(t => t.severity === 'HIGH')
     const overallRisk: TradeOffSummary['overallRisk'] =
@@ -73,20 +148,21 @@ export const MockAIService: IAIService = {
         items: tradeoffs.map(t => ({ concern: t.concern, severity: t.severity, mitigation: t.mitigation })),
         overallRisk,
       },
+      provenance: mockProvenance(),
     }
   },
 
-  async summarizeComparison(items: UnifiedMatchResult[]): Promise<ItemResponse<ComparisonSummary>> {
+  async summarizeComparison(items: UnifiedMatchResult[]): Promise<AIResponse<ComparisonSummary>> {
     await delay(SIMULATED_DELAY.medium)
-    return { data: buildComparisonSummary(items) }
+    return { data: buildComparisonSummary(items), provenance: mockProvenance() }
   },
 
-  async generateDecisionBrief(shortlistId: string): Promise<ItemResponse<DecisionBrief>> {
+  async generateDecisionBrief(shortlistId: string): Promise<AIResponse<DecisionBrief>> {
     await delay(SIMULATED_DELAY.slow)
-    return { data: buildMockDecisionBrief(shortlistId) }
+    return { data: buildMockDecisionBrief(shortlistId), provenance: mockProvenance() }
   },
 
-  async generateDataQualitySummary(_propertyId: string, quality: DataQualityInput): Promise<ItemResponse<DataQualitySummary>> {
+  async generateDataQualitySummary(_propertyId: string, quality: DataQualityInput): Promise<AIResponse<DataQualitySummary>> {
     await delay(SIMULATED_DELAY.fast)
     const level =
       quality.score >= 0.85 ? 'excellent'
@@ -113,10 +189,11 @@ export const MockAIService: IAIService = {
             : 'Keine sofortigen Massnahmen erforderlich.',
         confidence: quality.score,
       },
+      provenance: mockProvenance(),
     }
   },
 
-  async classifyMarketSignal(signalText: string): Promise<ItemResponse<MarketSignalClassification>> {
+  async classifyMarketSignal(signalText: string): Promise<AIResponse<MarketSignalClassification>> {
     await delay(SIMULATED_DELAY.medium)
     const t = signalText.toLowerCase()
     let signalType: MarketSignalClassification['signalType'] = 'UNKNOWN'
@@ -136,10 +213,11 @@ export const MockAIService: IAIService = {
         credibility: 'MEDIUM',
         reasoning: `Keyword-basierte Klassifikation (Mock). Signaltyp: ${signalType}.`,
       },
+      provenance: mockProvenance(),
     }
   },
 
-  async generateOfferEmail(payload: OfferEmailPayload): Promise<ItemResponse<{ subject: string; body: string }>> {
+  async generateOfferEmail(payload: OfferEmailPayload): Promise<AIResponse<{ subject: string; body: string }>> {
     await delay(SIMULATED_DELAY.medium * 2)
     return {
       data: {
@@ -149,11 +227,12 @@ export const MockAIService: IAIService = {
           payload.properties.map((p, i) => `• ${p} (Match-Score: ${payload.matchScores[i]}%)`).join('\n') +
           `\n\nGerne arrangieren wir Besichtigungstermine für die genannten Objekte und stehen für alle weiteren Fragen zur Verfügung.\n\nFreundliche Grüsse\nWincasa AG`,
       },
+      provenance: mockProvenance(),
     }
   },
 
   // Legacy methods
-  async extractCriteria(_input: string): Promise<ItemResponse<CriteriaExtractionResult>> {
+  async extractCriteria(_input: string): Promise<AIResponse<CriteriaExtractionResult>> {
     return {
       data: {
         extractedCriteria: {
@@ -170,15 +249,16 @@ export const MockAIService: IAIService = {
           'Wann möchten Sie spätestens einziehen?',
         ],
       },
+      provenance: mockProvenance(),
     }
   },
 
-  async generateFollowUp(partialNeed: Partial<CreateNeedInput>): Promise<ItemResponse<string[]>> {
+  async generateFollowUp(partialNeed: Partial<CreateNeedInput>): Promise<AIResponse<string[]>> {
     const questions: string[] = []
     if (!partialNeed.assetType) questions.push('Welchen Nutzungstyp suchen Sie?')
     if (!partialNeed.preferredLocations?.length) questions.push('In welchen Regionen suchen Sie?')
     if (!partialNeed.timing) questions.push('Was ist Ihr gewünschter Einzugstermin?')
     if (!partialNeed.budgetRange) questions.push('Was ist Ihr maximales monatliches Budget?')
-    return { data: questions }
+    return { data: questions, provenance: mockProvenance() }
   },
 }

src/services/ai/openrouter/OpenRouterAIService.ts

@@ -6,22 +6,24 @@
  *   VITE_OPENROUTER_API_KEY=<your-key>
  *   VITE_OPENROUTER_MODEL=anthropic/claude-3-5-haiku  (optional, default shown)
  *
- * All methods follow this contract:
- *   1. If API key is missing → explicit warn + MockAIService fallback
- *   2. If API call fails     → explicit error log + MockAIService fallback
- *   3. If JSON parse fails   → explicit warn + MockAIService fallback
- *   4. On success            → fully AI-generated response, no silent mock merge
+ * Every method follows this contract:
+ *   1. No API key        → warn + MockAIService fallback (fallbackUsed: true)
+ *   2. HTTP error        → error log + MockAIService fallback
+ *   3. JSON parse fail   → warn + MockAIService fallback
+ *   4. Zod schema fail   → warn + MockAIService fallback  ← NEW
+ *   5. Success (full AI) → AI response, source: 'ai', validationPassed: true
+ *   6. Hybrid            → source: 'hybrid', documented per-method
  *
- * Methods that use a hybrid approach (AI text merged into mock structure) are
- * explicitly documented with why mock data fills the remaining fields.
+ * No invalid data ever reaches the UI.
  */
-import type { ItemResponse } from '../../types'
 import type { CreateNeedInput } from '../../../domain/need'
 import type { ParseNeedResult, ParsedNeedCriteria, FollowUpQuestion } from '../../../domain/needBuilder'
 import type { UnifiedMatchResult } from '../../../domain/unifiedResult'
 import type { AssetType } from '../../../domain/enums'
 import type {
   IAIService,
+  AIResponse,
+  AIProvenance,
   DecisionBrief,
   ComparisonSummary,
   CriteriaExtractionResult,
@@ -36,6 +38,17 @@ import type {
 } from '../IAIService'
 import { ServiceErrorCode } from '../../types'
 import { AppError } from '../../errors'
+import {
+  NeedParsingResponseSchema,
+  FollowUpQuestionsResponseSchema,
+  TradeOffSummaryResponseSchema,
+  CompareSummaryResponseSchema,
+  DecisionBriefResponseSchema,
+  DataQualitySummaryResponseSchema,
+  MarketSignalClassificationResponseSchema,
+  OfferEmailResponseSchema,
+  validateAIResponse,
+} from '../schemas'
 import { buildNeedParsingPrompt } from '../prompts/needParsingPrompt'
 import { buildFollowUpQuestionsPrompt } from '../prompts/followUpQuestionsPrompt'
 import { buildMatchExplanationPrompt } from '../prompts/matchExplanationPrompt'
@@ -48,9 +61,9 @@ import { MockAIService } from '../mock/MockAIService'
 
 // ── Config ────────────────────────────────────────────────────────────────────
 
-const API_BASE = 'https://openrouter.ai/api/v1'
-const DEFAULT_MODEL = 'anthropic/claude-3-5-haiku'
-const PROMPT_VERSION = 'v1.0'
+const API_BASE       = 'https://openrouter.ai/api/v1'
+const DEFAULT_MODEL  = 'anthropic/claude-3-5-haiku'
+const PROMPT_VERSION = 'v1.1'
 const SCHEMA_VERSION = 'v1.0'
 
 interface OpenRouterConfig {
@@ -67,28 +80,45 @@ function getConfig(): OpenRouterConfig | null {
   }
 }
 
+function makeProvenance(
+  config: OpenRouterConfig,
+  source: AIProvenance['source'],
+  fallbackUsed: boolean,
+  validationPassed: boolean,
+): AIProvenance {
+  return {
+    provider: 'openrouter',
+    model: config.model,
+    generatedAt: new Date().toISOString(),
+    promptVersion: PROMPT_VERSION,
+    source,
+    fallbackUsed,
+    validationPassed,
+  }
+}
+
 // ── HTTP helper ───────────────────────────────────────────────────────────────
 
 async function chat(config: OpenRouterConfig, system: string, user: string): Promise<string> {
   const res = await fetch(`${API_BASE}/chat/completions`, {
     method: 'POST',
     headers: {
-      'Authorization': `Bearer ${config.apiKey}`,
-      'Content-Type': 'application/json',
-      'HTTP-Referer': window.location.origin,
+      'Authorization':  `Bearer ${config.apiKey}`,
+      'Content-Type':   'application/json',
+      'HTTP-Referer':   window.location.origin,
     },
     body: JSON.stringify({
       model: config.model,
       messages: [
         { role: 'system', content: system },
-        { role: 'user', content: user },
+        { role: 'user',   content: user   },
       ],
     }),
   })
   if (!res.ok) {
     const body = await res.text()
     throw new AppError({
-      code: ServiceErrorCode.AI_GENERATION_FAILED,
+      code:    ServiceErrorCode.AI_GENERATION_FAILED,
       message: `OpenRouter error ${res.status}: ${body}`,
     })
   }
@@ -99,8 +129,7 @@ async function chat(config: OpenRouterConfig, system: string, user: string): Pro
 // ── JSON extraction ───────────────────────────────────────────────────────────
 
 function extractJSON<T>(raw: string): T | null {
-  // Try fenced code block first, then bare object/array
-  const fenced = raw.match(/```(?:json)?\s*\n?([\s\S]*?)\n?```/)
+  const fenced    = raw.match(/```(?:json)?\s*\n?([\s\S]*?)\n?```/)
   const candidate = fenced ? fenced[1] : raw.match(/([\[{][\s\S]*[\]}])/)?.[1] ?? raw
   try {
     return JSON.parse(candidate) as T
@@ -109,7 +138,7 @@ function extractJSON<T>(raw: string): T | null {
   }
 }
 
-// ── Helpers for ParseNeedResult mapping ───────────────────────────────────────
+// ── ParseNeed helpers ─────────────────────────────────────────────────────────
 
 type RawNeedParseAI = {
   assetType?: string | null
@@ -124,12 +153,12 @@ type RawNeedParseAI = {
 
 function followUpForField(field: string): string {
   const MAP: Record<string, string> = {
-    assetType: 'Welchen Nutzungstyp suchen Sie (Büro, Retail, Logistik, Produktion)?',
-    areaRange: 'Welche Fläche benötigen Sie (min–max in m²)?',
+    assetType:          'Welchen Nutzungstyp suchen Sie (Büro, Retail, Logistik, Produktion)?',
+    areaRange:          'Welche Fläche benötigen Sie (min–max in m²)?',
     preferredLocations: 'In welchen Städten oder Regionen suchen Sie?',
-    budgetRange: 'Was ist Ihr maximales Budget pro m² und Jahr?',
-    timing: 'Wann möchten Sie spätestens einziehen?',
-    mustHaveCriteria: 'Haben Sie zwingende Anforderungen (ÖV-Anbindung, Parkplätze, Laderampe)?',
+    budgetRange:        'Was ist Ihr maximales Budget pro m² und Jahr?',
+    timing:             'Wann möchten Sie spätestens einziehen?',
+    mustHaveCriteria:   'Haben Sie zwingende Anforderungen (ÖV-Anbindung, Parkplätze, Laderampe)?',
   }
   return MAP[field] ?? `Können Sie "${field}" präzisieren?`
 }
@@ -145,23 +174,25 @@ function defaultSuggestedWeights(): Record<string, number> {
 
 // ── Fallback wrapper ──────────────────────────────────────────────────────────
 
-type FallbackFn<T> = () => Promise<ItemResponse<T>>
+type FallbackFn<T> = () => Promise<AIResponse<T>>
 
 async function withFallback<T>(
   label: string,
-  fn: (config: OpenRouterConfig) => Promise<ItemResponse<T>>,
+  fn: (config: OpenRouterConfig) => Promise<AIResponse<T>>,
   fallback: FallbackFn<T>,
-): Promise<ItemResponse<T>> {
+): Promise<AIResponse<T>> {
   const config = getConfig()
   if (!config) {
     console.warn(`[OpenRouterAIService] ${label}: no API key — using MockAIService`)
-    return fallback()
+    const result = await fallback()
+    return { ...result, provenance: { ...result.provenance, fallbackUsed: true } }
   }
   try {
     return await fn(config)
   } catch (err) {
     console.error(`[OpenRouterAIService] ${label} failed:`, err)
-    return fallback()
+    const result = await fallback()
+    return { ...result, provenance: { ...result.provenance, fallbackUsed: true } }
   }
 }
 
@@ -170,20 +201,24 @@ async function withFallback<T>(
 export const OpenRouterAIService: IAIService = {
 
   // ── parseNeed ───────────────────────────────────────────────────────────────
-  parseNeed(input: string): Promise<ItemResponse<ParseNeedResult>> {
+  parseNeed(input: string): Promise<AIResponse<ParseNeedResult>> {
     return withFallback('parseNeed', async (config) => {
       const { system, user } = buildNeedParsingPrompt({ userInput: input })
-      const raw = await chat(config, system, user)
-      const ai = extractJSON<RawNeedParseAI>(raw)
+      const raw  = await chat(config, system, user)
+      const json = extractJSON<RawNeedParseAI>(raw)
+      const ai   = json ? validateAIResponse(NeedParsingResponseSchema, json, 'parseNeed') : null
+
       if (!ai) {
-        console.warn('[OpenRouterAIService] parseNeed: could not parse JSON — using mock fallback')
-        return MockAIService.parseNeed(input)
+        console.warn('[OpenRouterAIService] parseNeed: invalid response — using mock fallback')
+        const fb = await MockAIService.parseNeed(input)
+        return { ...fb, provenance: makeProvenance(config, 'mock', true, false) }
       }
+
       const extractedCriteria: ParsedNeedCriteria = {
-        assetType: (ai.assetType ?? undefined) as AssetType | undefined,
-        areaRange: ai.areaRange ?? undefined,
+        assetType:          (ai.assetType ?? undefined) as AssetType | undefined,
+        areaRange:          ai.areaRange ?? undefined,
         preferredLocations: ai.preferredLocations,
-        budgetRange: ai.budgetRange ?? undefined,
+        budgetRange:        ai.budgetRange ?? undefined,
         timing: ai.timing
           ? { ...ai.timing, latestMoveIn: ai.timing.latestMoveIn ?? undefined }
           : undefined,
@@ -196,67 +231,71 @@ export const OpenRouterAIService: IAIService = {
       })
       missingFields.forEach(f => { confidenceByField[f] = 0 })
       const followUpQuestionCandidates: FollowUpQuestion[] = missingFields.map((field, i) => ({
-        id: `fq-or-${i}`,
+        id:          `fq-or-${i}`,
         questionText: followUpForField(field),
-        targetField: field,
-        reason: `Feld "${field}" nicht im Text erkannt`,
-        importance: 'recommended' as const,
+        targetField:  field,
+        reason:       `Feld "${field}" nicht im Text erkannt`,
+        importance:   'recommended' as const,
       }))
       return {
         data: {
           extractedCriteria,
           confidenceByField,
           missingFields,
-          assumptions: ai.assumptions ?? [],
-          suggestedWeights: defaultSuggestedWeights(),
+          assumptions:              ai.assumptions ?? [],
+          suggestedWeights:         defaultSuggestedWeights(),
           followUpQuestionCandidates,
-          rawSummary: raw.substring(0, 500),
-          promptVersion: PROMPT_VERSION,
-          schemaVersion: SCHEMA_VERSION,
+          rawSummary:               raw.substring(0, 500),
+          promptVersion:            PROMPT_VERSION,
+          schemaVersion:            SCHEMA_VERSION,
         },
+        provenance: makeProvenance(config, 'ai', false, true),
       }
     }, () => MockAIService.parseNeed(input))
   },
 
   // ── generateFollowUpQuestions ───────────────────────────────────────────────
-  generateFollowUpQuestions(criteria: ParsedNeedCriteria): Promise<ItemResponse<FollowUpQuestion[]>> {
+  generateFollowUpQuestions(criteria: ParsedNeedCriteria): Promise<AIResponse<FollowUpQuestion[]>> {
     return withFallback('generateFollowUpQuestions', async (config) => {
       const missingFields = Object.entries(criteria)
         .filter(([, v]) => v == null)
         .map(([k]) => k)
       const { system, user } = buildFollowUpQuestionsPrompt({ criteria, missingFields })
-      const raw = await chat(config, system, user)
-      type RawFQ = { questionText?: string; targetField?: string; reason?: string; suggestedAnswerOptions?: string[]; importance?: string }
-      const ai = extractJSON<RawFQ[]>(raw)
+      const raw  = await chat(config, system, user)
+      const json = extractJSON<unknown[]>(raw)
+      const ai   = json ? validateAIResponse(FollowUpQuestionsResponseSchema, json, 'generateFollowUpQuestions') : null
+
       if (!ai?.length) {
-        console.warn('[OpenRouterAIService] generateFollowUpQuestions: empty response — using mock fallback')
-        return MockAIService.generateFollowUpQuestions(criteria)
+        console.warn('[OpenRouterAIService] generateFollowUpQuestions: invalid response — using mock fallback')
+        const fb = await MockAIService.generateFollowUpQuestions(criteria)
+        return { ...fb, provenance: makeProvenance(config, 'mock', true, false) }
       }
       return {
         data: ai.map((q, i) => ({
-          id: `fq-or-${i}`,
-          questionText: q.questionText ?? '?',
-          targetField: q.targetField ?? 'unknown',
-          reason: q.reason ?? 'AI-generiert',
+          id:                     `fq-or-${i}`,
+          questionText:           q.questionText,
+          targetField:            q.targetField,
+          reason:                 q.reason ?? 'AI-generiert',
           suggestedAnswerOptions: q.suggestedAnswerOptions,
-          importance: (['required', 'recommended', 'optional'].includes(q.importance ?? '')
-            ? q.importance
-            : 'recommended') as FollowUpQuestion['importance'],
+          importance:             (q.importance ?? 'recommended') as FollowUpQuestion['importance'],
         })),
+        provenance: makeProvenance(config, 'ai', false, true),
       }
     }, () => MockAIService.generateFollowUpQuestions(criteria))
   },
 
   // ── generateMatchExplanation ────────────────────────────────────────────────
-  generateMatchExplanation(input: MatchExplanationInput): Promise<ItemResponse<MatchExplanation>> {
+  // Plain-text response — no JSON schema to validate, but non-empty check enforced.
+  generateMatchExplanation(input: MatchExplanationInput): Promise<AIResponse<MatchExplanation>> {
     return withFallback('generateMatchExplanation', async (config) => {
       const { system, user } = buildMatchExplanationPrompt(input)
-      const raw = await chat(config, system, user)
-      // matchExplanationPrompt returns plain text (max 3 sentences), not JSON
+      const raw     = await chat(config, system, user)
       const summary = raw.trim()
+
       if (!summary) {
         console.warn('[OpenRouterAIService] generateMatchExplanation: empty response — using mock fallback')
-        return MockAIService.generateMatchExplanation(input)
+        const fb = await MockAIService.generateMatchExplanation(input)
+        return { ...fb, provenance: makeProvenance(config, 'mock', true, false) }
       }
       const scoreLabel = input.matchScore >= 78 ? 'Starkes' : input.matchScore >= 52 ? 'Gutes' : 'Schwaches'
       return {
@@ -268,43 +307,43 @@ export const OpenRouterAIService: IAIService = {
             ...input.negativeFactors.slice(0, 1).map(f => `− ${f.explanation}`),
           ],
         },
+        provenance: makeProvenance(config, 'ai', false, true),
       }
     }, () => MockAIService.generateMatchExplanation(input))
   },
 
   // ── summarizeTradeOffs ──────────────────────────────────────────────────────
-  summarizeTradeOffs(tradeoffs: TradeOffInput[]): Promise<ItemResponse<TradeOffSummary>> {
+  summarizeTradeOffs(tradeoffs: TradeOffInput[]): Promise<AIResponse<TradeOffSummary>> {
     return withFallback('summarizeTradeOffs', async (config) => {
       const { system, user } = buildTradeOffPrompt(tradeoffs, 'Objekt')
-      const raw = await chat(config, system, user)
-      type RawTradeOff = {
-        headline?: string
-        items?: Array<{ concern?: string; severity?: string; mitigation?: string }>
-        overallRisk?: string
+      const raw  = await chat(config, system, user)
+      const json = extractJSON<unknown>(raw)
+      const ai   = json ? validateAIResponse(TradeOffSummaryResponseSchema, json, 'summarizeTradeOffs') : null
+
+      if (!ai) {
+        console.warn('[OpenRouterAIService] summarizeTradeOffs: invalid response — using mock fallback')
+        const fb = await MockAIService.summarizeTradeOffs(tradeoffs)
+        return { ...fb, provenance: makeProvenance(config, 'mock', true, false) }
       }
-      const ai = extractJSON<RawTradeOff>(raw)
-      if (!ai?.headline) {
-        console.warn('[OpenRouterAIService] summarizeTradeOffs: incomplete response — using mock fallback')
-        return MockAIService.summarizeTradeOffs(tradeoffs)
-      }
-      const validSeverity = (s?: string): 'LOW' | 'MEDIUM' | 'HIGH' =>
-        (['LOW', 'MEDIUM', 'HIGH'].includes(s ?? '') ? s : 'MEDIUM') as 'LOW' | 'MEDIUM' | 'HIGH'
       return {
         data: {
-          headline: ai.headline,
-          items: (ai.items ?? []).map(item => ({
-            concern: item.concern ?? '',
-            severity: validSeverity(item.severity),
+          headline:    ai.headline,
+          items:       ai.items.map(item => ({
+            concern:    item.concern,
+            severity:   item.severity,
             mitigation: item.mitigation,
           })),
-          overallRisk: validSeverity(ai.overallRisk),
+          overallRisk: ai.overallRisk,
         },
+        provenance: makeProvenance(config, 'ai', false, true),
       }
     }, () => MockAIService.summarizeTradeOffs(tradeoffs))
   },
 
   // ── summarizeComparison ─────────────────────────────────────────────────────
-  summarizeComparison(items: UnifiedMatchResult[]): Promise<ItemResponse<ComparisonSummary>> {
+  // Hybrid: AI provides narrative text; mock provides structural per-property data.
+  // source: 'hybrid' — both are labeled in provenance.
+  summarizeComparison(items: UnifiedMatchResult[]): Promise<AIResponse<ComparisonSummary>> {
     return withFallback('summarizeComparison', async (config) => {
       type ItemWithProp = UnifiedMatchResult & {
         property?: { title?: string; location?: { city?: string }; rentPricePerSqm?: number }
@@ -312,200 +351,199 @@ export const OpenRouterAIService: IAIService = {
       const properties = (items as ItemWithProp[])
         .filter(i => i.resultType !== 'FUTURE_AVAILABILITY')
         .map(i => ({
-          title: i.property?.title ?? `Match ${i.matchScore}`,
-          matchScore: i.matchScore,
-          city: i.property?.location?.city ?? '–',
-          rentPerSqm: i.property?.rentPricePerSqm ?? 0,
+          title:           i.property?.title ?? `Match ${i.matchScore}`,
+          matchScore:      i.matchScore,
+          city:            i.property?.location?.city ?? '–',
+          rentPerSqm:      i.property?.rentPricePerSqm ?? 0,
           positiveFactors: i.match.positiveFactors.slice(0, 2).map(f => f.explanation ?? f.criterion),
           negativeFactors: i.match.negativeFactors.slice(0, 2).map(f => f.explanation ?? f.criterion),
         }))
       const { system, user } = buildCompareSummaryPrompt({ properties })
-      const raw = await chat(config, system, user)
-      type RawComparison = {
-        overallAssessment?: string
-        recommendation?: string
-        strongestOption?: { matchId?: string; label?: string; reason?: string }
+      const raw  = await chat(config, system, user)
+      const json = extractJSON<unknown>(raw)
+      const ai   = json ? validateAIResponse(CompareSummaryResponseSchema, json, 'summarizeComparison') : null
+
+      if (!ai) {
+        console.warn('[OpenRouterAIService] summarizeComparison: invalid response — using mock fallback')
+        const fb = await MockAIService.summarizeComparison(items)
+        return { ...fb, provenance: makeProvenance(config, 'mock', true, false) }
       }
-      const ai = extractJSON<RawComparison>(raw)
-      if (!ai?.overallAssessment) {
-        console.warn('[OpenRouterAIService] summarizeComparison: incomplete response — using mock fallback')
-        return MockAIService.summarizeComparison(items)
-      }
-      // Hybrid: AI provides the narrative, mock provides the structural data (perPropertyAssessment etc.)
       const mock = await MockAIService.summarizeComparison(items)
       return {
         data: {
           ...mock.data,
           overallAssessment: ai.overallAssessment,
-          recommendation: ai.recommendation ?? mock.data.recommendation,
+          recommendation:    ai.recommendation ?? mock.data.recommendation,
         },
+        provenance: makeProvenance(config, 'hybrid', false, true),
       }
     }, () => MockAIService.summarizeComparison(items))
   },
 
   // ── generateDecisionBrief ───────────────────────────────────────────────────
-  generateDecisionBrief(shortlistId: string): Promise<ItemResponse<DecisionBrief>> {
+  // Hybrid: AI generates narrative summary + sections; mock fills structural metadata.
+  generateDecisionBrief(shortlistId: string): Promise<AIResponse<DecisionBrief>> {
     return withFallback('generateDecisionBrief', async (config) => {
       const { system, user } = buildDecisionBriefPrompt({ shortlistItems: [], needSummary: shortlistId })
-      const raw = await chat(config, system, user)
-      type RawBrief = {
-        summary?: string
-        sections?: Array<{ title?: string; body?: string }>
-      }
-      const ai = extractJSON<RawBrief>(raw)
-      if (!ai?.summary) {
-        console.warn('[OpenRouterAIService] generateDecisionBrief: incomplete response — using mock fallback')
-        return MockAIService.generateDecisionBrief(shortlistId)
+      const raw  = await chat(config, system, user)
+      const json = extractJSON<unknown>(raw)
+      const ai   = json ? validateAIResponse(DecisionBriefResponseSchema, json, 'generateDecisionBrief') : null
+
+      if (!ai) {
+        console.warn('[OpenRouterAIService] generateDecisionBrief: invalid response — using mock fallback')
+        const fb = await MockAIService.generateDecisionBrief(shortlistId)
+        return { ...fb, provenance: makeProvenance(config, 'mock', true, false) }
       }
       const mock = await MockAIService.generateDecisionBrief(shortlistId)
       return {
         data: {
           ...mock.data,
-          summary: ai.summary,
-          sections: ai.sections?.map(s => ({
-            title: s.title ?? '',
-            body: s.body ?? '',
-          })) ?? mock.data.sections,
+          summary:  ai.summary,
+          sections: ai.sections.map(s => ({ title: s.title, body: s.body })),
         },
+        provenance: makeProvenance(config, 'hybrid', false, true),
       }
     }, () => MockAIService.generateDecisionBrief(shortlistId))
   },
 
   // ── generateDataQualitySummary ──────────────────────────────────────────────
-  generateDataQualitySummary(propertyId: string, quality: DataQualityInput): Promise<ItemResponse<DataQualitySummary>> {
+  generateDataQualitySummary(propertyId: string, quality: DataQualityInput): Promise<AIResponse<DataQualitySummary>> {
     return withFallback('generateDataQualitySummary', async (config) => {
       const { system, user } = buildDataQualityPrompt(propertyId, quality)
-      const raw = await chat(config, system, user)
-      type RawDQ = {
-        overallAssessment?: string
-        missingCriticalFields?: string[]
-        recommendation?: string
-        confidence?: number
-      }
-      const ai = extractJSON<RawDQ>(raw)
-      if (!ai?.overallAssessment) {
-        console.warn('[OpenRouterAIService] generateDataQualitySummary: incomplete response — using mock fallback')
-        return MockAIService.generateDataQualitySummary(propertyId, quality)
+      const raw  = await chat(config, system, user)
+      const json = extractJSON<unknown>(raw)
+      const ai   = json ? validateAIResponse(DataQualitySummaryResponseSchema, json, 'generateDataQualitySummary') : null
+
+      if (!ai) {
+        console.warn('[OpenRouterAIService] generateDataQualitySummary: invalid response — using mock fallback')
+        const fb = await MockAIService.generateDataQualitySummary(propertyId, quality)
+        return { ...fb, provenance: makeProvenance(config, 'mock', true, false) }
       }
       return {
         data: {
-          overallAssessment: ai.overallAssessment,
+          overallAssessment:     ai.overallAssessment,
           missingCriticalFields: ai.missingCriticalFields ?? quality.missingCriticalFields,
-          recommendation: ai.recommendation ?? '',
-          confidence: typeof ai.confidence === 'number' ? ai.confidence : quality.score,
+          recommendation:        ai.recommendation,
+          confidence:            ai.confidence,
         },
+        provenance: makeProvenance(config, 'ai', false, true),
       }
     }, () => MockAIService.generateDataQualitySummary(propertyId, quality))
   },
 
   // ── classifyMarketSignal ────────────────────────────────────────────────────
-  classifyMarketSignal(signalText: string): Promise<ItemResponse<MarketSignalClassification>> {
+  classifyMarketSignal(signalText: string): Promise<AIResponse<MarketSignalClassification>> {
     return withFallback('classifyMarketSignal', async (config) => {
       const { system, user } = buildMarketSignalPrompt(signalText)
-      const raw = await chat(config, system, user)
-      type RawSignal = {
-        signalType?: string
-        probability?: number
-        timeHorizonMonths?: number | null
-        areaSqmEstimate?: number | null
-        credibility?: string
-        reasoning?: string
+      const raw  = await chat(config, system, user)
+      const json = extractJSON<unknown>(raw)
+      const ai   = json
+        ? validateAIResponse(MarketSignalClassificationResponseSchema, json, 'classifyMarketSignal')
+        : null
+
+      if (!ai) {
+        console.warn('[OpenRouterAIService] classifyMarketSignal: invalid response — using mock fallback')
+        const fb = await MockAIService.classifyMarketSignal(signalText)
+        return { ...fb, provenance: makeProvenance(config, 'mock', true, false) }
       }
-      const ai = extractJSON<RawSignal>(raw)
-      if (!ai?.signalType) {
-        console.warn('[OpenRouterAIService] classifyMarketSignal: incomplete response — using mock fallback')
-        return MockAIService.classifyMarketSignal(signalText)
-      }
-      const validSignalType = (s?: string): MarketSignalClassification['signalType'] => {
-        const valid: MarketSignalClassification['signalType'][] =
-          ['VACANCY', 'CONSTRUCTION', 'RESTRUCTURING', 'EXPANSION', 'RELOCATION', 'UNKNOWN']
-        return (valid.includes(s as MarketSignalClassification['signalType']) ? s : 'UNKNOWN') as MarketSignalClassification['signalType']
-      }
-      const validCredibility = (s?: string): 'LOW' | 'MEDIUM' | 'HIGH' =>
-        (['LOW', 'MEDIUM', 'HIGH'].includes(s ?? '') ? s : 'MEDIUM') as 'LOW' | 'MEDIUM' | 'HIGH'
       return {
         data: {
-          signalType: validSignalType(ai.signalType),
-          probability: typeof ai.probability === 'number'
-            ? Math.min(1, Math.max(0, ai.probability))
-            : 0.5,
-          timeHorizonMonths: typeof ai.timeHorizonMonths === 'number' ? ai.timeHorizonMonths : null,
-          areaSqmEstimate: typeof ai.areaSqmEstimate === 'number' ? ai.areaSqmEstimate : null,
-          credibility: validCredibility(ai.credibility),
-          reasoning: ai.reasoning ?? '',
+          signalType:        ai.signalType,
+          probability:       ai.probability,
+          timeHorizonMonths: ai.timeHorizonMonths ?? null,
+          areaSqmEstimate:   ai.areaSqmEstimate ?? null,
+          credibility:       ai.credibility,
+          reasoning:         ai.reasoning,
         },
+        provenance: makeProvenance(config, 'ai', false, true),
       }
     }, () => MockAIService.classifyMarketSignal(signalText))
   },
 
   // ── generateOfferEmail ──────────────────────────────────────────────────────
-  generateOfferEmail(payload: OfferEmailPayload): Promise<ItemResponse<{ subject: string; body: string }>> {
+  generateOfferEmail(payload: OfferEmailPayload): Promise<AIResponse<{ subject: string; body: string }>> {
     return withFallback('generateOfferEmail', async (config) => {
       const propertyList = payload.properties
         .map((p, i) => `• ${p} (Match-Score: ${payload.matchScores[i]}%)`)
         .join('\n')
       const system = `Du bist Immobilienmakler bei Wincasa AG. Erstelle eine professionelle, knappe Angebotsmail auf Deutsch. Antworte als JSON: { "subject": "...", "body": "..." }`
-      const user = `Suchanfrage: "${payload.needTitle}"\n\nObjekte:\n${propertyList}\n\nErstelle eine professionelle Angebotsmail.`
-      const raw = await chat(config, system, user)
-      type RawEmail = { subject?: string; body?: string }
-      const ai = extractJSON<RawEmail>(raw)
-      if (!ai?.subject || !ai?.body) {
-        console.warn('[OpenRouterAIService] generateOfferEmail: incomplete response — using mock fallback')
-        return MockAIService.generateOfferEmail(payload)
+      const user   = `Suchanfrage: "${payload.needTitle}"\n\nObjekte:\n${propertyList}\n\nErstelle eine professionelle Angebotsmail.`
+      const raw    = await chat(config, system, user)
+      const json   = extractJSON<unknown>(raw)
+      const ai     = json ? validateAIResponse(OfferEmailResponseSchema, json, 'generateOfferEmail') : null
+
+      if (!ai) {
+        console.warn('[OpenRouterAIService] generateOfferEmail: invalid response — using mock fallback')
+        const fb = await MockAIService.generateOfferEmail(payload)
+        return { ...fb, provenance: makeProvenance(config, 'mock', true, false) }
+      }
+      return {
+        data:      { subject: ai.subject, body: ai.body },
+        provenance: makeProvenance(config, 'ai', false, true),
       }
-      return { data: { subject: ai.subject, body: ai.body } }
     }, () => MockAIService.generateOfferEmail(payload))
   },
 
   // ── Legacy: extractCriteria ─────────────────────────────────────────────────
-  extractCriteria(input: string): Promise<ItemResponse<CriteriaExtractionResult>> {
+  extractCriteria(input: string): Promise<AIResponse<CriteriaExtractionResult>> {
     return withFallback('extractCriteria', async (config) => {
       const { system, user } = buildNeedParsingPrompt({ userInput: input })
-      const raw = await chat(config, system, user)
-      const ai = extractJSON<RawNeedParseAI>(raw)
+      const raw  = await chat(config, system, user)
+      const json = extractJSON<RawNeedParseAI>(raw)
+      const ai   = json ? validateAIResponse(NeedParsingResponseSchema, json, 'extractCriteria') : null
+
       if (!ai) {
-        console.warn('[OpenRouterAIService] extractCriteria: could not parse JSON — using mock fallback')
-        return MockAIService.extractCriteria(input)
+        console.warn('[OpenRouterAIService] extractCriteria: invalid response — using mock fallback')
+        const fb = await MockAIService.extractCriteria(input)
+        return { ...fb, provenance: makeProvenance(config, 'mock', true, false) }
       }
       return {
         data: {
           extractedCriteria: {
-            assetType: ai.assetType as AssetType | undefined ?? undefined,
-            requiredArea: ai.areaRange ?? undefined,
+            assetType:          ai.assetType as AssetType | undefined ?? undefined,
+            requiredArea:       ai.areaRange ?? undefined,
             preferredLocations: ai.preferredLocations ?? [],
-            budgetRange: ai.budgetRange ?? undefined,
+            budgetRange:        ai.budgetRange ?? undefined,
           },
-          confidence: 0.80,
-          missingFields: ai.missingFields ?? [],
-          assumptions: ai.assumptions ?? [],
-          followUpQuestions: (ai.missingFields ?? []).map(followUpForField),
+          confidence:         0.80,
+          missingFields:      ai.missingFields ?? [],
+          assumptions:        ai.assumptions ?? [],
+          followUpQuestions:  (ai.missingFields ?? []).map(followUpForField),
         },
+        provenance: makeProvenance(config, 'ai', false, true),
       }
     }, () => MockAIService.extractCriteria(input))
   },
 
   // ── Legacy: generateFollowUp ────────────────────────────────────────────────
-  generateFollowUp(partialNeed: Partial<CreateNeedInput>): Promise<ItemResponse<string[]>> {
+  generateFollowUp(partialNeed: Partial<CreateNeedInput>): Promise<AIResponse<string[]>> {
     return withFallback('generateFollowUp', async (config) => {
       const missingFields = [
-        ...(!partialNeed.assetType ? ['assetType'] : []),
+        ...(!partialNeed.assetType             ? ['assetType']          : []),
         ...(!partialNeed.preferredLocations?.length ? ['preferredLocations'] : []),
-        ...(!partialNeed.timing ? ['timing'] : []),
-        ...(!partialNeed.budgetRange ? ['budgetRange'] : []),
+        ...(!partialNeed.timing                ? ['timing']             : []),
+        ...(!partialNeed.budgetRange           ? ['budgetRange']        : []),
       ]
-      if (!missingFields.length) return { data: [] }
+      if (!missingFields.length) {
+        return { data: [], provenance: makeProvenance(config, 'ai', false, true) }
+      }
       const { system, user } = buildFollowUpQuestionsPrompt({
         criteria: partialNeed as ParsedNeedCriteria,
         missingFields,
       })
-      const raw = await chat(config, system, user)
-      type RawFQ = { questionText?: string }
-      const ai = extractJSON<RawFQ[]>(raw)
+      const raw  = await chat(config, system, user)
+      const json = extractJSON<unknown[]>(raw)
+      const ai   = json ? validateAIResponse(FollowUpQuestionsResponseSchema, json, 'generateFollowUp') : null
+
       if (!ai?.length) {
-        console.warn('[OpenRouterAIService] generateFollowUp: empty response — using mock fallback')
-        return MockAIService.generateFollowUp(partialNeed)
+        console.warn('[OpenRouterAIService] generateFollowUp: invalid response — using mock fallback')
+        const fb = await MockAIService.generateFollowUp(partialNeed)
+        return { ...fb, provenance: makeProvenance(config, 'mock', true, false) }
+      }
+      return {
+        data:      ai.map(q => q.questionText).filter(Boolean),
+        provenance: makeProvenance(config, 'ai', false, true),
       }
-      return { data: ai.map(q => q.questionText ?? '').filter(Boolean) }
     }, () => MockAIService.generateFollowUp(partialNeed))
   },
 }

src/services/ai/prompts/decisionBriefPrompt.ts

@@ -11,12 +11,42 @@ export interface DecisionBriefPromptInput {
 }
 
 export function buildDecisionBriefPrompt(input: DecisionBriefPromptInput): { system: string; user: string } {
-  const itemList = input.shortlistItems
-    .map(i => `- ${i.title} (${i.city}): Score ${i.matchScore}%, ${i.areaSqm}m², CHF ${i.rentPerSqm}/m² — ${i.topReasons.join(', ')}`)
-    .join('\n')
+  const itemList = input.shortlistItems.length > 0
+    ? input.shortlistItems
+        .map(i => `- ${i.title} (${i.city}): Score ${i.matchScore}%, ${i.areaSqm}m², CHF ${i.rentPerSqm}/m² — ${i.topReasons.join(', ')}`)
+        .join('\n')
+    : '(keine Objekte auf der Shortlist)'
 
-  return {
-    system: `Du bist Senior Real Estate Advisor. Erstelle ein strukturiertes Entscheidungs-Briefing auf Deutsch als JSON mit: summary, sections (Zusammenfassung, Standortbewertung, Budgetanalyse, Empfohlene nächste Schritte).`,
-    user: `Erstelle ein Entscheidungs-Briefing für folgende Shortlist:\n\nSuchprofil: ${input.needSummary}\n\nObjekte:\n${itemList}`,
-  }
+  const system = `Du bist Senior Real Estate Advisor bei Wincasa AG. Du erstellst strukturierte Entscheidungs-Briefings für Unternehmenskunden auf Deutsch.
+
+WICHTIG — Konfidenzregeln:
+- Schreibe nur, was durch die Daten belegt ist. Verwende "scheint", "deutet darauf hin", "laut Datenlage" wenn du Einschätzungen machst.
+- Stelle keine Verfügbarkeit als gesichert dar, wenn sie nicht explizit bestätigt ist.
+- Unterscheide zwischen Stärken ("erfüllt vollständig") und Hinweisen ("Tendenz erkennbar").
+
+AUSGABEFORMAT — antworte ausschliesslich als valides JSON (kein Markdown, keine Erklärungen):
+{
+  "summary": "1–2 Sätze Executive Summary",
+  "sections": [
+    { "title": "Zusammenfassung", "body": "Überblick über die Shortlist und Gesamtbewertung" },
+    { "title": "Standortbewertung", "body": "Vergleich der Standorte nach Erreichbarkeit, Prestige, Eignung" },
+    { "title": "Budgetanalyse", "body": "Kostenvergleich und Budget-Effizienz der Objekte" },
+    { "title": "Empfohlene nächste Schritte", "body": "Konkrete, priorisierte Handlungsempfehlungen" }
+  ]
+}
+
+Regeln:
+- Genau 4 Sektionen, Reihenfolge wie oben
+- summary: max 2 Sätze
+- body jeder Sektion: 2–4 Sätze, entscheidungsorientiert
+- Kein JSON in Markdown-Codeblöcken`
+
+  const user = `Erstelle ein Entscheidungs-Briefing für folgende Shortlist:
+
+Suchprofil: ${input.needSummary}
+
+Objekte:
+${itemList}`
+
+  return { system, user }
 }

src/services/ai/prompts/matchExplanationPrompt.ts

@@ -5,15 +5,32 @@ export interface MatchExplanationPromptInput {
   positiveFactors: Array<{ criterion: string; explanation: string }>
   negativeFactors: Array<{ criterion: string; explanation: string }>
   needSummary: string
+  isFutureSignal?: boolean
 }
 
 export function buildMatchExplanationPrompt(input: MatchExplanationPromptInput): { system: string; user: string } {
-  return {
-    system: `Du bist ein Experte für Schweizer Gewerbeimmobilien. Erkläre Match-Ergebnisse präzise und entscheidungsorientiert auf Deutsch. Maximal 3 Sätze.`,
-    user: `Erkläre warum das Objekt "${input.propertyTitle}" in ${input.propertyCity} einen Match Score von ${input.matchScore}% hat.
+  const confidenceNote = input.isFutureSignal
+    ? '\nDieses Objekt ist ein Zukunftssignal (noch nicht verfügbar). Stelle die Verfügbarkeit NICHT als gesichert dar. Verwende Formulierungen wie "könnte verfügbar werden", "Signal deutet auf mögliche Fläche hin".'
+    : ''
 
-Stärken: ${input.positiveFactors.map(f => f.explanation).join(', ')}
-Schwächen: ${input.negativeFactors.map(f => f.explanation).join(', ')}
-Suchprofil: ${input.needSummary}`,
-  }
+  const system = `Du bist Experte für Schweizer Gewerbeimmobilien bei Wincasa AG. Du erklärst Match-Ergebnisse präzise und entscheidungsorientiert auf Deutsch.
+
+Konfidenz-Vokabular:
+- Score ≥ 78: "starkes Match", "erfüllt die Kernkriterien", "klar empfehlenswert"
+- Score 52–77: "gutes Match mit Kompromissen", "weitgehend geeignet", "einzelne Einschränkungen"
+- Score < 52: "schwaches Match", "deutliche Abweichungen", "kritische Lücken"
+
+Regeln:
+- Maximal 3 Sätze
+- Nenne die 1–2 stärksten Gründe für den Score
+- Erwähne die grösste Einschränkung, falls vorhanden
+- Keine allgemeinen Floskeln ("ein attraktives Objekt") — nur konkrete Fakten aus den Score-Faktoren${confidenceNote}`
+
+  const user = `Erkläre warum das Objekt "${input.propertyTitle}" in ${input.propertyCity} einen Match-Score von ${input.matchScore}/100 hat.
+
+Stärken: ${input.positiveFactors.map(f => f.explanation).join('; ')}
+Schwächen: ${input.negativeFactors.map(f => f.explanation).join('; ')}
+Suchprofil: ${input.needSummary}`
+
+  return { system, user }
 }

src/services/ai/schemas.ts

@@ -0,0 +1,149 @@
+/**
+ * Zod schemas for all AI response types.
+ *
+ * Every OpenRouter response is validated against its schema before reaching
+ * the UI. Validation failures trigger an explicit fallback to MockAIService —
+ * no invalid data ever passes through silently.
+ */
+import { z } from 'zod'
+
+// ── Shared primitives ─────────────────────────────────────────────────────────
+
+export const SeveritySchema   = z.enum(['LOW', 'MEDIUM', 'HIGH'])
+export const CredibilitySchema = z.enum(['LOW', 'MEDIUM', 'HIGH'])
+
+/** Probability must be strictly within [0, 1] — no -5, no 1.5 */
+export const ProbabilitySchema = z.number().min(0).max(1)
+
+/** Match score must be within [0, 100] */
+export const ScoreSchema = z.number().min(0).max(100)
+
+// ── 1. Need Parsing ───────────────────────────────────────────────────────────
+
+export const NeedParsingResponseSchema = z.object({
+  assetType: z
+    .enum(['OFFICE', 'RETAIL', 'LOGISTICS', 'PRODUCTION', 'GASTRO', 'MIXED', 'UNKNOWN'])
+    .optional()
+    .nullable(),
+  areaRange: z
+    .object({ min: z.number().min(0), max: z.number().min(0) })
+    .optional()
+    .nullable()
+    .refine(r => r == null || r.max >= r.min, { message: 'areaRange.max must be >= min' }),
+  preferredLocations: z.array(z.string().min(1)).optional(),
+  budgetRange: z
+    .object({ maxPerSqm: z.number().positive(), currency: z.string().min(1) })
+    .optional()
+    .nullable(),
+  timing: z
+    .object({
+      earliestMoveIn: z.string().optional(),
+      latestMoveIn:   z.string().optional(),
+      flexibleTiming: z.boolean().optional(),
+    })
+    .optional()
+    .nullable(),
+  mustHaveCriteria: z.array(z.string()).optional(),
+  missingFields:    z.array(z.string()).optional(),
+  assumptions:      z.array(z.string()).optional(),
+})
+
+export type NeedParsingResponseRaw = z.infer<typeof NeedParsingResponseSchema>
+
+// ── 2. Follow-Up Questions ────────────────────────────────────────────────────
+
+export const FollowUpQuestionsResponseSchema = z
+  .array(
+    z.object({
+      questionText:          z.string().min(1),
+      targetField:           z.string().min(1),
+      reason:                z.string().optional(),
+      suggestedAnswerOptions: z.array(z.string()).optional(),
+      importance: z
+        .enum(['required', 'recommended', 'optional'])
+        .optional(),
+    }),
+  )
+  .max(5)
+
+// ── 3. Trade-Off Summary ──────────────────────────────────────────────────────
+
+export const TradeOffSummaryResponseSchema = z.object({
+  headline: z.string().min(1),
+  items: z
+    .array(
+      z.object({
+        concern:    z.string().min(1),
+        severity:   SeveritySchema,
+        mitigation: z.string().optional(),
+      }),
+    )
+    .max(5),
+  overallRisk: SeveritySchema,
+})
+
+// ── 4. Comparison Summary ─────────────────────────────────────────────────────
+
+export const CompareSummaryResponseSchema = z.object({
+  overallAssessment: z.string().min(1),
+  recommendation:    z.string().optional(),
+  strongestOption:   z.string().optional(),
+})
+
+// ── 5. Decision Brief ────────────────────────────────────────────────────────
+
+export const DecisionBriefResponseSchema = z.object({
+  summary: z.string().min(1),
+  sections: z
+    .array(z.object({ title: z.string().min(1), body: z.string().min(1) }))
+    .min(1)
+    .max(6),
+})
+
+// ── 6. Data Quality Summary ───────────────────────────────────────────────────
+
+export const DataQualitySummaryResponseSchema = z.object({
+  overallAssessment:    z.string().min(1),
+  missingCriticalFields: z.array(z.string()).optional(),
+  recommendation:       z.string().min(1),
+  confidence:           z.number().min(0).max(1),
+})
+
+// ── 7. Market Signal Classification ──────────────────────────────────────────
+
+export const MarketSignalClassificationResponseSchema = z.object({
+  signalType: z.enum([
+    'VACANCY', 'CONSTRUCTION', 'RESTRUCTURING',
+    'EXPANSION', 'RELOCATION', 'UNKNOWN',
+  ]),
+  probability:       ProbabilitySchema,
+  timeHorizonMonths: z.number().positive().int().optional().nullable(),
+  areaSqmEstimate:   z.number().positive().optional().nullable(),
+  credibility:       CredibilitySchema,
+  reasoning:         z.string().min(1),
+})
+
+// ── 8. Offer Email ────────────────────────────────────────────────────────────
+
+export const OfferEmailResponseSchema = z.object({
+  subject: z.string().min(1),
+  body:    z.string().min(10),
+})
+
+// ── Validation helper ─────────────────────────────────────────────────────────
+
+/**
+ * Validates raw AI JSON against a Zod schema.
+ * Returns the parsed value on success, or null on failure.
+ * Logs a structured warning on failure — never throws.
+ */
+export function validateAIResponse<T>(
+  schema: z.ZodType<T>,
+  raw: unknown,
+  label: string,
+): T | null {
+  const result = schema.safeParse(raw)
+  if (result.success) return result.data
+  console.warn(`[AISchema] ${label} validation failed:`, result.error.flatten())
+  return null
+}