Implement Tree Editor with visual preview and documentation updates

Tree Editor Features:
- Zustand store with immer middleware and zundo for undo/redo
- Form-based node editing (Decision, Action, Solution types)
- Visual tree preview with solution connection indicators
- NodePicker with type-grouped dropdown (Decisions/Actions/Solutions)
- SharedLinksMap for detecting nodes with multiple sources
- Modal component with scrollable body, fixed header/footer

New Components:
- TreeEditorLayout, TreeMetadataForm, NodeList, NodeEditorModal
- NodeFormDecision, NodeFormAction, NodeFormResolution
- DynamicArrayField, NodePicker
- TreePreviewPanel, TreePreviewNode

Documentation:
- Updated README.md status to Phase 2
- Added Tree Editor details to CURRENT-STATE.md
- Added modal/Zustand lessons to LESSONS-LEARNED.md
- Updated file structure in CLAUDE-SETUP.md
- Added Tree Editor progress to PROGRESS.md

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

README.md

@@ -2,9 +2,11 @@
 
 > Transform chaos into clarity - guided troubleshooting with automatic documentation for MSP engineers.
 
-## Project Status: 📋 Planning Phase
+## Project Status: 🚀 Phase 2 - Active Development
 
-Currently in the planning and architecture phase. Development will begin once key decisions are made and initial troubleshooting scenarios are documented.
+**Backend**: Complete and tested (18 API endpoints, 40+ integration tests)
+**Frontend**: Core features complete, Tree Editor in progress
+**Tree Editor**: Visual editor with form-based editing and live preview panel
 
 ---
 
@@ -315,39 +317,35 @@ Options being considered:
 ## Roadmap at a Glance
 
 ```
-└─ [📋 Planning] ← WE ARE HERE
-   ├─ 📝 Document requirements
+└─ [✅ Planning] COMPLETE
+   ├─ ✅ Document requirements
    ├─ ✅ Make key decisions
-   └─ 🏗️ Setup initial architecture
-   
-└─ [🚀 Week 1-3: MVP]
-   ├─ Basic tree navigation
-   ├─ Export functionality
-   └─ 5 starter trees
-   
-└─ [👥 Week 4-6: Team Ready]
-   ├─ Team management
-   ├─ Tree editor
-   └─ Mobile responsive
-   
-└─ [💼 Week 7-12: Professional]
+   └─ ✅ Setup initial architecture
+
+└─ [✅ Phase 1: MVP] COMPLETE
+   ├─ ✅ Backend API (18 endpoints)
+   ├─ ✅ Tree navigation UI
+   ├─ ✅ Session tracking
+   └─ ✅ Export functionality
+
+└─ [🚀 Phase 2: Team Ready] ← IN PROGRESS
+   ├─ ✅ Tree Editor (form-based with preview)
+   ├─ ⏳ Team management
+   └─ ⏳ Mobile responsive
+
+└─ [📋 Phase 3: Professional]
    ├─ Attachments
    ├─ Offline mode
    └─ Analytics
-   
-└─ [🔌 Month 4-6: Platform]
+
+└─ [📋 Phase 4: Platform]
    ├─ API & integrations
    ├─ Automation
    └─ Enterprise features
-   
-└─ [🚀 Beyond: Growth]
-   ├─ Marketplace
-   ├─ AI features
-   └─ Mobile apps
 ```
 
 ---
 
-**Last Updated:** 2026-01-22  
-**Project Status:** Planning Phase  
-**Next Milestone:** Answer key questions, document first 3 troubleshooting scenarios
+**Last Updated:** 2026-01-28
+**Project Status:** Phase 2 - Active Development
+**Next Milestone:** Complete Tree Editor polishing, Team management features