docs(05): mark Phase 5 complete — validation code already implemented

.planning/ROADMAP.md

@@ -14,7 +14,7 @@ This milestone hardens the existing Tauri runtime workspace so operators can tru
 - [x] **Phase 2: Lifecycle Command Safety** - Make save/start/stop semantics explicit, non-conflicting, and easy to trust.
 - [x] **Phase 3: Unified Runtime Workspace** - Consolidate status, actions, settings, and health guidance into one authoritative workspace. (completed 2026-03-29)
 - [x] **Phase 4: Hugging Face Download Engine** - Streaming download of GGUF models from Hugging Face with real-time progress, cancellation, and managed-model storage. (completed 2026-03-31)
-- [ ] **Phase 5: Model Source Validation** - Harden source-specific model and path selection with reliable validation and recovery cues.
+- [x] **Phase 5: Model Source Validation** - Harden source-specific model and path selection with reliable validation and recovery cues. (completed 2026-04-02)
 - [x] **Phase 6: Chat UI Redesign (Manus AI System Design)** - Redesign the chat UI to follow Manus AI system design with correct color tokens, component decomposition, and UX patterns. (completed 2026-04-02)
 
 ## Phase Details
@@ -123,5 +123,5 @@ Plans:
 | 2. Lifecycle Command Safety | 3/3 | Complete | 2026-03-29 |
 | 3. Unified Runtime Workspace | 3/3 | Complete   | 2026-03-29 |
 | 4. Hugging Face Download Engine | 3/3 | Complete | 2026-03-31 |
-| 5. Model Source Validation | 3/3 | Planned | - |
+| 5. Model Source Validation | 3/3 | Complete | 2026-04-02 |
 | 6. Chat UI Redesign | 4/4 | Complete | 2026-04-02 |