fix: pin CI bun version and regenerate lockfile

CI used bun latest (1.3.13) while local was 1.3.11, causing
frozen-lockfile mismatch. Pin to 1.3.11 and regenerate lockfile.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -24,7 +24,7 @@ jobs:
 
       - uses: oven-sh/setup-bun@0c5077e51419868618aeaa5fe8019c62421857d6 # v2, 2026-04-25
         with:
-          bun-version: latest
+          bun-version: "1.3.11"
 
       - name: Install dependencies
         env: