ci: narrow files-changed frontend filter (#37749)

Drop the broad `tools/*.{js,ts}` globs from the `frontend` filter so
edits to CI-only or backend helper scripts in `tools/` stop triggering
frontend and e2e jobs. Only `tools/generate-svg.ts` is kept.

Also renames `tools/lint-pr-title.js` to `.ts` for consistency, drops
the empty root `*.js` glob, fixes stray indentation in the `dockerfile`
filter and adds missing `setup-node`.

---
This PR was written with the help of Claude Opus 4.7

---------

Co-authored-by: Claude (Opus 4.7) <noreply@anthropic.com>

.github/workflows/files-changed.yml

@@ -63,11 +63,9 @@ jobs:
               - "options/locale/locale_en-US.json"
 
             frontend:
-              - "*.js"
               - "*.ts"
               - "web_src/**"
-              - "tools/*.js"
-              - "tools/*.ts"
+              - "tools/generate-svg.ts"
               - "assets/emoji.json"
               - "package.json"
               - "pnpm-lock.yaml"
@@ -99,8 +97,8 @@ jobs:
               - "Makefile"
 
             dockerfile:
-                - "Dockerfile"
-                - "Dockerfile.rootless"
+              - "Dockerfile"
+              - "Dockerfile.rootless"
 
             swagger:
               - "templates/swagger/v1_json.tmpl"