feat: add chat components from jarvis frontend

- Migrated Chat.tsx with message handling and UI structure
- Migrated ChatInput.tsx with character limits and keyboard shortcuts
- Migrated MessageList.tsx with thinking/reasoning display
- Migrated ConversationSidebar.tsx (simplified placeholder)
- Migrated BackendStatusBanner.tsx (simplified placeholder)
- Created components/chat/index.ts barrel export
- Created app/chat/page.tsx placeholder route

These components are adapted from jarvis-fe but not yet fully functional:
- API calls placeholder (need to wire up /api/brain/query)
- Auth hooks stubbed (need useAuth implementation)
- Project/conversation hooks stubbed (need implementation)
- Imports changed from @jarvis/* to @mosaic/*

Next steps:
- Implement missing hooks (useAuth, useProjects, useConversations, useApi)
- Wire up backend API endpoints
- Add proper TypeScript types
- Implement full conversation management

MINDMAP_MIGRATION.md

@@ -0,0 +1,118 @@
+# Mindmap Components Migration - Phase 3
+
+**Status:** ✅ Complete (with notes)  
+**Commit:** `aa267b5` - "feat: add mindmap components from jarvis frontend"  
+**Branch:** `feature/jarvis-fe-migration`
+
+## Completed Tasks
+
+### 1. ✅ Directory Structure Created
+```
+apps/web/src/components/mindmap/
+├── controls/
+│   ├── ExportButton.tsx
+│   └── NodeCreateModal.tsx
+├── hooks/
+│   └── useGraphData.ts
+├── nodes/
+│   ├── BaseNode.tsx
+│   ├── ConceptNode.tsx
+│   ├── IdeaNode.tsx
+│   ├── ProjectNode.tsx
+│   └── TaskNode.tsx
+├── index.ts
+├── MermaidViewer.tsx
+├── MindmapViewer.tsx
+└── ReactFlowEditor.tsx
+```
+
+### 2. ✅ Components Copied
+All mindmap components have been successfully migrated:
+- **Main viewers:** ReactFlowEditor, MindmapViewer, MermaidViewer
+- **Node types:** BaseNode, ConceptNode, TaskNode, IdeaNode, ProjectNode
+- **Controls:** NodeCreateModal, ExportButton
+- **Hooks:** useGraphData (with KnowledgeNode, KnowledgeEdge types)
+
+### 3. ✅ Barrel Export Created
+`components/mindmap/index.ts` exports all components and types for clean imports
+
+### 4. ✅ Route Created
+- Created `/mindmap` page at `apps/web/src/app/mindmap/page.tsx`
+- Includes proper metadata and layout
+
+### 5. ✅ Dependencies Added
+- Copied `lib/auth-client.ts` (BetterAuth integration)
+- Created `lib/api.ts` (session management utilities)
+
+## Import Updates
+
+No `@jarvis/*` imports were present in the mindmap components - they were already using relative paths and `@/lib/*` aliases, which are compatible with the Mosaic structure.
+
+## Type Adaptations
+
+The mindmap uses its own `KnowledgeNode` and `KnowledgeEdge` types, which are specific to the knowledge graph feature and not part of the general Mosaic entity types (Task, Project, etc. from `@mosaic/shared`). This is correct as the mindmap represents a different data model.
+
+## Known Issues & Next Steps
+
+### Missing Package Dependencies
+The build currently fails due to missing packages required by `auth-client.ts`:
+```
+better-auth
+better-auth/react
+better-auth-credentials-plugin
+better-auth-credentials-plugin/client
+```
+
+**Resolution:** These packages need to be added to the workspace:
+```bash
+pnpm add better-auth better-auth-credentials-plugin
+```
+
+### ReactFlow Dependencies
+Verify that `@xyflow/react` is installed:
+```bash
+pnpm add @xyflow/react
+```
+
+### Mermaid Dependency
+Verify that `mermaid` is installed:
+```bash
+pnpm add mermaid
+```
+
+## Testing Checklist
+
+Once dependencies are installed:
+- [ ] Build completes without errors
+- [ ] Navigate to `/mindmap` route
+- [ ] Create a knowledge node
+- [ ] Verify ReactFlow interactive editor renders
+- [ ] Test Mermaid diagram view
+- [ ] Test export functionality
+- [ ] Verify node type rendering (Concept, Task, Idea, Project)
+
+## API Integration
+
+The mindmap components expect a backend knowledge graph API at:
+- Base URL: `process.env.NEXT_PUBLIC_API_URL` (default: http://localhost:8000)
+- Endpoints:
+  - `GET /api/v1/knowledge/graph` - Fetch graph data
+  - `GET /api/v1/knowledge/mermaid` - Fetch Mermaid diagram
+  - `POST /api/v1/knowledge/nodes` - Create node
+  - `PUT /api/v1/knowledge/nodes/:id` - Update node
+  - `DELETE /api/v1/knowledge/nodes/:id` - Delete node
+  - `POST /api/v1/knowledge/edges` - Create edge
+  - `DELETE /api/v1/knowledge/edges` - Delete edge
+  - `GET /api/v1/knowledge/graph/statistics` - Get statistics
+
+## Files Changed
+- 15 files added
+- 1,758 insertions
+- No deletions
+
+## Git Info
+```
+Branch: feature/jarvis-fe-migration
+Commit: aa267b5
+Pushed: Yes
+```