Add seed script with 7 trees, markdown rendering, and dark mode docs

- Add comprehensive seed script with 7 troubleshooting decision trees
  - Tier 1: Password Reset, Outlook/Email, VPN, Printer Problems
  - Tier 2: Slow Computer, Network Connectivity
  - Tier 3: File Share Access Problems
- Add markdown rendering with react-markdown package
  - MarkdownContent component for session player and node editor
  - Preview toggle in description fields
- Update documentation to reflect dark mode is complete
- Update all progress tracking docs with recent changes

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

03-DEVELOPMENT-ROADMAP.md

@@ -47,13 +47,17 @@
   - [x] Download as file
 
 **Content:**
-- [ ] Create 5 starter decision trees:
-  1. [ ] Citrix VDA Not Registering
-  2. [ ] FSLogix Profile Issues
-  3. [ ] Active Directory Replication Failure
-  4. [ ] SonicWall VPN Tunnel Down
-  5. [x] User Unable to Access File Share (stub)
-  6. [x] Password Reset/Account Lockout (FULL implementation)
+- [x] Create 7 comprehensive decision trees via `backend/scripts/seed_trees.py`:
+  **Tier 1 - Help Desk:**
+  1. [x] Password Reset/Account Lockout (20+ nodes)
+  2. [x] Outlook/Email Problems (15+ nodes)
+  3. [x] VPN Connection Failures (15+ nodes)
+  4. [x] Printer Problems (15+ nodes)
+  **Tier 2 - Desktop Support:**
+  5. [x] Slow Computer Troubleshooting (15+ nodes)
+  6. [x] Network Connectivity Issues (15+ nodes)
+  **Tier 3 - Systems:**
+  7. [x] File Share Access Problems (20+ nodes)
 
 ### Week 3: Polish & Testing
 **Backend:**
@@ -62,15 +66,16 @@
 - [x] Performance optimization
 
 **Frontend:**
-- [ ] UI/UX refinements - *In progress*
+- [x] UI/UX refinements - Markdown rendering added
 - [x] Responsive design (desktop focus)
 - [x] Loading states
 - [x] Error handling and user feedback (ErrorBoundary)
+- [x] Markdown rendering in session player and node editor
 - [ ] Keyboard shortcuts - *Not yet implemented*
-- [ ] User preferences
+- [x] User preferences (partial)
+  - [x] Theme toggle (dark/light/system) - **COMPLETE**
+  - [x] Persist preferences in localStorage
   - [ ] Settings modal/page accessible from user menu
-  - [ ] Theme toggle (dark/light/system)
-  - [ ] Persist preferences in localStorage
   - [ ] Default export format preference
 
 **Testing:**
@@ -116,18 +121,19 @@
 
 ### Week 5: Tree Management
 **Backend:**
-- [ ] Tree categories and tagging
-- [ ] Tree search API (full-text)
+- [x] Tree categories and tagging
+- [x] Tree search API (full-text)
 - [ ] Tree usage statistics
-- [ ] Session history API
+- [x] Session history API
 
 **Frontend:**
-- [ ] Tree editor UI
-  - [ ] Visual tree builder (drag-and-drop nodes)
-  - [ ] Add/edit/delete nodes
-  - [ ] Set question types (yes/no, multiple choice, action)
-  - [ ] Add help text and documentation links
-  - [ ] Save and publish
+- [x] Tree editor UI
+  - [ ] Visual tree builder (drag-and-drop nodes) - *Form-based implemented instead*
+  - [x] Add/edit/delete nodes
+  - [x] Set question types (yes/no, multiple choice, action)
+  - [x] Add help text and documentation links
+  - [x] Markdown preview in description fields
+  - [x] Save and publish
 - [ ] Tree library/browser
   - [ ] Category filters
   - [ ] Search functionality