Unify project draft thread state in composer draft store

- move project draft thread ID persistence/actions into `composerDraftStore`
- remove legacy `projectDraftThreads` module and update `ChatView`/`Sidebar` callers
- keep image dedupe stable across hydration and avoid revoking blob URLs on composer clear
- add store tests for project-thread mapping and composer clear behavior
- drop deprecated model slug aliases (`gpt-5`, `gpt-5-codex`, `gpt-5-codex-spark`)
b59c6d6ab1Julius Marminge committed on 3/2/2026, 6:36:35 AM· committed by Julius Marmingeparentc999599
6 files changedLine totals unavailable