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.

Implementation:
- Added alphabetical sorting with case-insensitive comparison
- Used localeCompare() for proper string comparison
- Sort happens immediately after fetching models from backend
- Currently selected model remains selected after sorting

Technical Details:
- Sort logic: models.sort((a, b) => a.toLowerCase().localeCompare(b.toLowerCase()))
- Frontend-only change, no backend modifications needed
- Sorting preserves model selection state

Acceptance Criteria Met:
✅ Models sorted alphabetically (case-insensitive)
✅ Selected model remains selected after sorting
✅ Works for all models from Ollama
✅ Updates correctly when models change

Files Changed:
- src/components/Chat.tsx: Added sorting logic to model fetch
- .living_spec/stories/23_alphabetize_llm_dropdown.md: Marked complete

.living_spec/stories/23_alphabetize_llm_dropdown.md

@@ -4,10 +4,10 @@
 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
+- [x] The model dropdown list is sorted alphabetically (case-insensitive)
+- [x] The currently selected model remains selected after sorting
+- [x] The sorting works for all models returned from Ollama
+- [x] The sorted list updates correctly when models are added/removed
 
 ## Out of Scope
 - Grouping models by type or provider