Add User Preferences to MVP, add Phase 2.5 Personal Branching specs

- Fixed minor typescript errors that would show during compile

04-FEATURE-SPECIFICATIONS.md

@@ -274,6 +274,52 @@ Started Citrix VDA service after resolving NetLogon dependency issue. VDA succes
 
 ---
 
+### 5.5 User Preferences (MVP)
+
+**Description:** Basic user settings to personalize the application experience, stored locally for MVP with optional server sync in later phases.
+
+**MVP Settings:**
+
+| Setting | Options | Default | Storage |
+|---------|---------|---------|--------|
+| Theme | Light / Dark / System | System | localStorage |
+| Default Export Format | Markdown / Text / HTML | Markdown | localStorage |
+
+**UI Components:**
+- **Settings Access:** Gear icon in user menu dropdown
+- **Settings Modal:** Simple modal with toggle/dropdown for each setting
+- **Theme Toggle:** Can also be quick-access icon in header
+
+**Theme Implementation:**
+```
+Light Mode:
+- Background: White/light gray
+- Text: Dark gray/black
+- Accents: Brand colors
+
+Dark Mode:
+- Background: Dark gray (#1a1a2e or similar)
+- Text: Light gray/white
+- Accents: Adjusted brand colors for dark backgrounds
+
+System:
+- Follows OS preference via prefers-color-scheme media query
+- Updates automatically if OS setting changes
+```
+
+**Technical Requirements:**
+- Persist to localStorage immediately on change
+- Apply theme without page reload (CSS variables)
+- Respect system preference on first visit
+- Export format preference used as default in export dialog
+
+**Future Enhancements (Phase 2+):**
+- Sync preferences to user account (database)
+- More settings: auto-save interval, keyboard shortcuts, notification preferences
+- Per-tree preferences (remember last used export format per tree)
+
+---
+
 ### 5. Attachment Support
 
 **Description:** Upload and attach files (screenshots, logs, command outputs) to specific decision nodes during troubleshooting.
@@ -724,6 +770,7 @@ Public and team steps can be rated by users to surface the most helpful content.
 | Tree Navigation | ✓ | | | | |
 | Basic Export | ✓ | | | | |
 | User Auth | ✓ | | | | |
+| **User Preferences** | **✓** | | | | |
 | 5 Starter Trees | ✓ | | | | |
 | Team Management | | ✓ | | | |
 | Tree Editor | | ✓ | | | |