The page's script is TypeScript in web/src, built and minified with swc

- web/src/*.ts: the script that was inline in index.html and login.html, split along its
  existing sections. Still one scope, concatenated in order, not modules.
- web/build.mjs strips the types, puts the script in the page and minifies it with swc;
  build.rs runs it into OUT_DIR and web.rs include_str!s the result. 137 KB -> 106 KB.
- npx tsc -p . type-checks web/src, loosely; the handful of annotations it needed
  change no behaviour.
- The Docker build installs node and swc (npm ci --omit=dev).
- Two list requests racing no longer let the older one win, and switching tabs clears
  the selection it closes, which made a browser test flaky.

Closes #23, #24.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

.gitignore

@@ -2,3 +2,4 @@
 /node_modules
 /test-results
 /playwright-report
+/web/dist