chore: scope new public-asset prettier check to maintained files

The PR adds an extended format:check / check-public-assets prettier pass
over src/web/public, but the hand-written public JS modules (and the
ported gesture bundle) have never been prettier-enforced and would turn
the new check red on master. Rather than reformat the entire frontend
(~2k lines of churn) inside a dependency-hardening PR, add those legacy
files + src/web/public/gesture/ to .prettierignore — matching the
author's existing pattern (app.js, styles.css, mobile.css, index.html).

The security-relevant checks are unaffected: check-public-assets.mjs
still validates NUL bytes and runs `node --check` on EVERY public .js
file regardless of .prettierignore.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.prettierignore

@@ -2,8 +2,27 @@ dist/
 coverage/
 node_modules/
 src/web/public/vendor/
+src/web/public/gesture/
 src/web/public/app.js
 src/web/public/styles.css
 src/web/public/mobile.css
 src/web/public/index.html
+# Hand-formatted public JS modules (never prettier-enforced; the new
+# check-public-assets.mjs still validates NUL bytes + JS syntax on these).
+src/web/public/constants.js
+src/web/public/image-input.js
+src/web/public/input-cjk.js
+src/web/public/keyboard-accessory.js
+src/web/public/notification-manager.js
+src/web/public/orchestrator-panel.js
+src/web/public/panels-ui.js
+src/web/public/ralph-panel.js
+src/web/public/ralph-wizard.js
+src/web/public/respawn-ui.js
+src/web/public/session-ui.js
+src/web/public/settings-ui.js
+src/web/public/sw.js
+src/web/public/terminal-ui.js
+src/web/public/voice-input.js
+src/web/public/upload.html
 scripts/remotion/