refactor: move PipelineItems from Zustand to Provider→Service→React Query

PipelineItems are domain data and must not live in Zustand. Moves the
full stack to the correct layer: MockupPipelineProvider (localStorage
persistence + seed fallback) → pipelineService → usePipeline hooks
(useQuery for reads, useMutation for writes with cache invalidation).

pipelineStore is now UI-only: dialogOpen, pendingItem, openSavedDialog,
closeSavedDialog. All consumers updated to use the new hooks.

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

src/components/pipeline/PipelineDetailPanel.tsx

@@ -7,7 +7,7 @@ import {
   AlertTriangle, ChevronRight, CheckCircle, ExternalLink, FileText,
   MapPin, MessageSquare, Sparkles, StickyNote, X,
 } from 'lucide-react'
-import { usePipelineStore } from '../../stores/pipelineStore'
+import { useMoveStage, useUpdateNotes, useLoseItem } from '../../hooks/usePipeline'
 import type { PipelineItem } from '../../domain/pipeline'
 import { STAGES, NEXT_STAGE, MOCK_DOCS } from './pipelineConstants'
 import { scoreColor, detailPath, getKiInsight } from './pipelineUtils'
@@ -16,7 +16,9 @@ import { scoreColor, detailPath, getKiInsight } from './pipelineUtils'
 
 export function DetailPanel({ item, onClose }: { item: PipelineItem; onClose: () => void }) {
   const navigate = useNavigate()
-  const { moveStage, updateNotes, loseItem } = usePipelineStore()
+  const { mutate: moveStage } = useMoveStage()
+  const { mutate: updateNotes } = useUpdateNotes()
+  const { mutate: loseItem } = useLoseItem()
   const path = detailPath(item)
   const [notes, setNotes] = useState(item.notes ?? '')
   const stageConfig = STAGES.find(s => s.key === item.stage)!
@@ -128,7 +130,7 @@ export function DetailPanel({ item, onClose }: { item: PipelineItem; onClose: ()
             <Box sx={{ display: 'flex', gap: 1, flexWrap: 'wrap' }}>
               {nextStage && (
                 <Button size="small" variant="contained" endIcon={<ChevronRight size={14} />}
-                  onClick={() => moveStage(item.id, nextStage.key)}
+                  onClick={() => moveStage({ id: item.id, stage: nextStage.key })}
                   sx={{ bgcolor: stageConfig.color, '&:hover': { filter: 'brightness(0.9)' }, fontSize: '0.75rem', py: 0.5 }}
                 >
                   {nextStage.label}
@@ -157,7 +159,7 @@ export function DetailPanel({ item, onClose }: { item: PipelineItem; onClose: ()
             placeholder="Notiz hinzufügen…"
             value={notes}
             onChange={e => setNotes(e.target.value)}
-            onBlur={() => updateNotes(item.id, notes)}
+            onBlur={() => updateNotes({ id: item.id, notes })}
             sx={{ '& .MuiOutlinedInput-root': { fontSize: '0.8rem', borderRadius: 1.5 } }}
           />
         </Box>