Story 22: Implement smart auto-scroll that respects user scrolling

User Story:
As a user, I want to be able to scroll up to review previous messages
while the AI is streaming or adding new content, without being
constantly dragged back to the bottom.

Implementation:
- Replaced position-based threshold detection with user-intent tracking
- Detects when user scrolls UP and disables auto-scroll completely
- Auto-scroll only re-enables when user manually returns to bottom (<5px)
- Uses refs to track scroll position and direction for smooth operation
- Works seamlessly during rapid token streaming and tool execution

Technical Details:
- lastScrollTopRef: Tracks previous scroll position to detect direction
- userScrolledUpRef: Flag set when upward scrolling is detected
- Direct scrollTop manipulation for instant, non-fighting scroll behavior
- Threshold of 5px from absolute bottom to re-enable auto-scroll

Spec Updates:
- Added comprehensive Smart Auto-Scroll section to UI_UX.md
- Documented the problem, solution, requirements, and implementation
- Includes code examples and edge case handling

Acceptance Criteria Met:
✅ Auto-scroll disabled when scrolling up
✅ Auto-scroll resumes when returning to bottom
✅ Works normally when already at bottom
✅ Smooth detection without flickering
✅ Works during streaming and tool execution

Files Changed:
- src/components/Chat.tsx: Implemented user-intent tracking
- .living_spec/specs/functional/UI_UX.md: Added Smart Auto-Scroll spec
- .living_spec/stories/22_smart_autoscroll.md: Marked complete

.living_spec/stories/23_alphabetize_llm_dropdown.md

@@ -0,0 +1,36 @@
+# Story 23: Alphabetize LLM Dropdown List
+
+## User Story
+As a user, I want the LLM model dropdown to be alphabetically sorted so I can quickly find the model I'm looking for.
+
+## Acceptance Criteria
+- [ ] The model dropdown list is sorted alphabetically (case-insensitive)
+- [ ] The currently selected model remains selected after sorting
+- [ ] The sorting works for all models returned from Ollama
+- [ ] The sorted list updates correctly when models are added/removed
+
+## Out of Scope
+- Grouping models by type or provider
+- Custom sort orders (e.g., by popularity, recency)
+- Search/filter functionality in the dropdown
+- Favoriting or pinning specific models to the top
+
+## Technical Notes
+- Models are fetched from `get_ollama_models` Tauri command
+- Currently displayed in the order returned by the backend
+- Sort should be case-insensitive (e.g., "Llama" and "llama" treated equally)
+- JavaScript's `sort()` with `localeCompare()` is ideal for this
+
+## Implementation Approach
+```tsx
+// After fetching models from backend
+const sortedModels = models.sort((a, b) => 
+  a.toLowerCase().localeCompare(b.toLowerCase())
+);
+setAvailableModels(sortedModels);
+```
+
+## Design Considerations
+- Keep it simple - alphabetical order is intuitive
+- Case-insensitive to handle inconsistent model naming
+- No need to change backend - sorting on frontend is sufficient