fix: Compare→Pipeline flow, pipeline card navigation, remove floating AI button

- Remove CompareTray fixed bottom bar; replace with compare count badge on Vergleich nav item
- Pipeline cards redesigned to match search result card visual style (MatchScoreDisplay, type chip, stage chip, MapPin layout)
- CompareColumnHeader: redesigned with proper Details/Merken action buttons, clickable title
- AddToPipelineDialog now mounted on Compare page (was missing — bookmark had no effect)
- Pipeline card ExternalLink icon navigates to property detail page; detailPath prefers stable propertyId over volatile session matchId
- Add matchId field to PipelineItem domain; pipelineStore stores it on save
- All 8 mock pipeline items now have propertyId for reliable cross-session navigation
- Remove GlobalAIAssistantButton floating overlay (was blocking form submissions and clicks)

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

src/components/layout/AppShell.tsx

@@ -46,10 +46,10 @@ import { OrganizationContextBadge } from './OrganizationContextBadge'
 import { UserMenu } from './UserMenu'
 import { NotificationButton } from './NotificationButton'
 import { RightContextPanel } from './RightContextPanel'
-import { CompareTray } from './CompareTray'
-import { GlobalAIAssistantDrawer, GlobalAIAssistantButton } from '../assistant'
+import { GlobalAIAssistantDrawer } from '../assistant'
 import { useAssistantStore } from '../../stores/assistantStore'
 import { ToastProvider } from '../ui'
+import { useCompareStore } from '../../stores/compareStore'
 
 // ---------------------------------------------------------------------------
 // Types
@@ -181,6 +181,7 @@ function Sidebar({
   orgName,
 }: SidebarProps) {
   const config = WORKSPACE_CONFIG[activeWorkspace]
+  const compareCount = useCompareStore(s => s.compareItems.length)
   const width = collapsed ? 60 : 264
   const visibleWorkspaces = WORKSPACE_ORDER.filter((ws) => allowedWorkspaces.includes(ws))
 
@@ -337,17 +338,30 @@ function Sidebar({
                 >
                   <Icon size={16} color={isActive ? TEXT_WHITE : TEXT_MUTED} />
                   {!collapsed && (
-                    <Typography
-                      variant="body2"
-                      sx={{
-                        color: isActive ? TEXT_WHITE : TEXT_MUTED,
-                        fontWeight: isActive ? 500 : 400,
-                        fontSize: '0.8125rem',
-                        whiteSpace: 'nowrap',
-                      }}
-                    >
-                      {item.label}
-                    </Typography>
+                    <Box sx={{ flex: 1, display: 'flex', alignItems: 'center', gap: 0.75, minWidth: 0 }}>
+                      <Typography
+                        variant="body2"
+                        sx={{
+                          color: isActive ? TEXT_WHITE : TEXT_MUTED,
+                          fontWeight: isActive ? 500 : 400,
+                          fontSize: '0.8125rem',
+                          whiteSpace: 'nowrap',
+                        }}
+                      >
+                        {item.label}
+                      </Typography>
+                      {item.path === '/demand/compare' && compareCount > 0 && (
+                        <Box sx={{
+                          minWidth: 18, height: 18, borderRadius: '9px',
+                          bgcolor: '#d97706', color: 'white',
+                          fontSize: '0.65rem', fontWeight: 700,
+                          display: 'flex', alignItems: 'center', justifyContent: 'center',
+                          px: 0.5, flexShrink: 0,
+                        }}>
+                          {compareCount}
+                        </Box>
+                      )}
+                    </Box>
                   )}
                 </Box>
               )}
@@ -605,9 +619,7 @@ export function AppShell() {
         <RightContextPanel />
       </Box>
 
-      <CompareTray />
       <GlobalAIAssistantDrawer />
-      <GlobalAIAssistantButton />
       <ToastProvider />
       <WelcomeDialog />
     </Box>