feat(swift): implementeer artifact lifecycle management (E4.S2)

Epic 4 Story 2 compleet: Meerdere artifacts met open/close/switch werken!

E4.S2 - Artifact Lifecycle Management (3 SP)
- Store state: openArtifacts[], activeArtifactId
- Store actions met max 3 artifacts logica
- ArtifactArea refactor naar ArtifactContainer
- CommandCenter integration met nieuwe artifact system

Store Updates (stores/swift-store.ts):
- openArtifacts: Artifact[] — Array van open artifacts
- activeArtifactId: string | null — Currently active artifact
- Initial state: [], null

Store Actions:
```typescript
openArtifact(artifact: Omit<Artifact, 'id' | 'createdAt'>) {
  // Auto-generate ID + timestamp
  // Max 3 artifacts: remove oldest if at capacity
  // Set new artifact as active
}

closeArtifact(id: string) {
  // Filter out artifact
  // Auto-switch to last remaining if closing active
}

switchArtifact(id: string) {
  // Verify artifact exists
  // Set activeArtifactId
}

closeAllArtifacts() {
  // Clear all artifacts + active ID
}
```

Features:
- Max 3 artifacts enforced (oldest removed at capacity)
- Auto-switch when closing active artifact
- Console logging voor debugging
- ID generation met crypto.randomUUID()
- Timestamp tracking met createdAt

Components Updated:
- components/swift/artifacts/artifact-area.tsx (30 regels)
  - Simplified: alleen ArtifactContainer rendering
  - Props: openArtifacts, activeArtifactId, switchArtifact, closeArtifact

- components/swift/command-center/command-center.tsx
  - openArtifact() i.p.v. openBlock()
  - getArtifactTitle() voor dynamic titles
  - Escape: closeAllArtifacts() i.p.v. closeBlock()
  - Artifact opening met title generation

Integration Flow:
1. Chat: AI genereert action met artifact data
2. ChatPanel: setPendingAction(action)
3. CommandCenter: useEffect detecteert pendingAction
4. CommandCenter: getArtifactTitle(type, prefill)
5. CommandCenter: openArtifact({ type, prefill, title })
6. Store: Auto-generate ID, check max 3, add to array
7. ArtifactArea: Renders ArtifactContainer met artifacts
8. ArtifactContainer: Shows tabs (if >1), renders active block

Console Logging:
- "[Store] Max 3 artifacts reached, removing oldest"
- "[Store] Opening artifact: dagnotitie Dagnotitie - Jan"
- "[Store] Closing artifact: [id] New active: [id]"
- "[Store] Switching to artifact: [id]"
- "[Store] Cannot switch to artifact: [id] (not found)"

Build Status:
- ✅ pnpm build succesvol (geen type errors)
- Alleen bekende warnings (Supabase realtime, useCallback)

Voortgang: 56 SP / 85 SP (66%) - 18/31 stories compleet, 2 geskipt

Next: E4.S3 (Slide-in animatie) - 200ms ease-out transitions

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docs/swift/bouwplan-swift-v3.md

@@ -222,12 +222,12 @@ const useChatStore = create<ChatState>((set) => ({
 | E1 | Foundation - Split-screen | Layout naar 40/60 split | ✅ **Compleet** | 3/3 | 12 SP | E1.S1 geskipt (geen feature flag) |
 | E2 | Chat Panel & Messages | Chat UI zonder AI | ✅ **Compleet** | 5/5 | 13 SP | Scrolling, input, shortcuts |
 | E3 | Chat API & Medical Scribe | AI conversatie werkend | ✅ **Compleet** | 6/6 | 21 SP | Artifact opening werkend! |
-| E4 | Artifact Area & Tabs | Meerdere artifacts mogelijk | ⏳ In Progress | 1/4 | 13 SP | Container & tabs structure |
+| E4 | Artifact Area & Tabs | Meerdere artifacts mogelijk | ⏳ In Progress | 2/4 | 13 SP | Lifecycle management werkend |
 | E5 | AI-Filtering & Polish | Psychiater filtering, polish | ⏳ To Do | 0/5 | 13 SP | Week 6 |
 | E6 | Testing & Refinement | QA, bugs, performance | ⏳ To Do | 0/4 | 8 SP | Week 7-8 |
 
 **Totaal:** 31 stories, **85 Story Points** (~7 weken à 12 SP/week)
-**Voortgang:** ✅ 17/31 stories compleet, 2 geskipt (53 SP / 85 SP = **62%**)
+**Voortgang:** ✅ 18/31 stories compleet, 2 geskipt (56 SP / 85 SP = **66%**)
 
 **Belangrijk:**
 - ⚠️ Voer niet in 1x het volledige plan uit. Bouw per epic en per story.
@@ -613,7 +613,7 @@ E3.S5 (useChatStream hook) is geskipt omdat:
 | Story ID | Beschrijving | Acceptatiecriteria | Status | Afhankelijkheden | Story Points |
 |----------|--------------|---------------------|--------|------------------|--------------|
 | E4.S1 | ArtifactContainer component | Wrapper met tabs bovenaan, max 3 artifacts | ✅ **Compleet** | E3.S6 | 5 |
-| E4.S2 | Artifact lifecycle management | Open/close/switch tussen artifacts in store | ⏳ | E4.S1 | 3 |
+| E4.S2 | Artifact lifecycle management | Open/close/switch tussen artifacts in store | ✅ **Compleet** | E4.S1 | 3 |
 | E4.S3 | Slide-in animatie | Artifact slide-in van rechts (200ms ease-out) | ⏳ | E4.S2 | 2 |
 | E4.S4 | Placeholder state | "Artifacts verschijnen hier" met voorbeelden | ⏳ | E4.S3 | 3 |
 
@@ -739,7 +739,27 @@ function ArtifactPlaceholder() {
 **Git Commits:**
 - (to be committed) — E4.S1 (ArtifactContainer component)
 
-**Note:** E4.S1 definieert de structuur. E4.S2 voegt store state toe (openArtifacts[], activeArtifactId, actions).
+**Deliverables (E4.S2 compleet):**
+- ✅ `stores/swift-store.ts` — openArtifacts[], activeArtifactId state
+- ✅ Store actions: openArtifact(), closeArtifact(), switchArtifact(), closeAllArtifacts()
+- ✅ openArtifact: Auto-generate ID + timestamp, max 3 logic (remove oldest)
+- ✅ closeArtifact: Filter out artifact, auto-switch to last remaining
+- ✅ switchArtifact: Verify exists, set activeArtifactId
+- ✅ closeAllArtifacts: Clear all artifacts + active ID
+- ✅ Console logging: "[Store] Opening artifact:", "[Store] Closing artifact:", etc.
+- ✅ ArtifactArea: Refactored to use ArtifactContainer
+- ✅ ArtifactArea: Pass store actions (switchArtifact, closeArtifact)
+- ✅ CommandCenter: openArtifact() i.p.v. openBlock()
+- ✅ CommandCenter: getArtifactTitle() voor artifact titles
+- ✅ CommandCenter: Escape key → closeAllArtifacts()
+- ✅ Integration: Chat → Action → openArtifact → Tabs + Container
+- ✅ Build succesvol zonder errors
+
+**Git Commits:**
+- `855744c` — E4.S1 (ArtifactContainer component)
+- (to be committed) — E4.S2 (Artifact lifecycle management)
+
+**Note:** E4.S1 + E4.S2 maken het artifact systeem volledig functioneel. E4.S3 voegt animaties toe.
 
 **Deliverable Epic 4 complete:** Meerdere artifacts mogelijk, smooth transitions, placeholder state