fix: exclude nested worktree directories from vitest

Running the suite from the main checkout was picking up each
worktree's full copy of src/ under .claude/worktrees/, silently
running every test twice. The existing supabase/functions/** exclude
only matched at repo root, so it also missed the nested worktree's
copy of that path.

Claude-Session: https://claude.ai/code/session_01NhxA4npAXAxmCDEJt6kxSH

vite.config.ts

@@ -14,7 +14,12 @@ export default defineConfig({
       '**/cypress/**',
       '**/.{idea,git,cache,output,temp}/**',
       '**/{karma,rollup,webpack,vite,vitest,jest,ava,babel,nyc,cypress,tsup,build}.config.*',
-      'supabase/functions/**',
+      '**/supabase/functions/**',
+      // Git worktrees for in-progress branches live nested under .claude/worktrees/
+      // in this project's dev setup — without this, running vitest from the main
+      // checkout also picks up each worktree's full copy of src/, duplicating
+      // every test (and, for worktrees mid-migration, potentially failing ones).
+      '**/.claude/worktrees/**',
     ],
   },
 })