Fix: anchor lib/ ignore patterns to repo root, add web/src/lib/utils.ts

The catch-all `lib/` pattern in both .gitignore and .dockerignore (intended
to exclude Python venv lib dirs) silently swallowed `web/src/lib/utils.ts`.
That's why every Docker build got "ENOENT /web/src/lib/utils" — the file
was never committed and never copied into the container, but local builds
worked because the file existed on disk.

Anchor `lib/` and `lib64/` to the repo root with `/lib/` and `/lib64/`,
then add the previously-ignored utils.ts.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.dockerignore

@@ -15,8 +15,8 @@ dist/
 downloads/
 eggs/
 .eggs/
-lib/
-lib64/
+/lib/
+/lib64/
 parts/
 sdist/
 var/