fix: correct marquee scroll speed and add code TODOs

- Fixed scrolling marquee to use a fixed px/s speed via JS instead of
  a fixed duration, preventing it from speeding up as entries are added
- Added inline TODO comments throughout codebase to track known issues
  (rate limiting, CSRF, unbounded queries, deprecated Flask decorator,
  PII logging, schema versioning, Docker non-root user, etc.)
- Added todo-to-issue GitHub Action to auto-create Issues from TODOs on push to main
- Added .claude/ to .gitignore

.github/workflows/todo-to-issue.yml

@@ -0,0 +1,14 @@
+name: TODO to Issue
+
+on:
+  push:
+    branches: [ "main" ]
+
+jobs:
+  todo:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: alstr/todo-to-issue-action@v5
+        with:
+          TOKEN: ${{ secrets.GITHUB_TOKEN }}