feat: optimize email filtering with frontend-only search (#787)

* feat: optimize email filtering with frontend-only search

- Remove backend keyword parameter from mail APIs (breaking change)
- Implement frontend filtering on current page (20-100 items)
- Add message_id database index for UPDATE performance
- Support desktop and mobile responsive layouts
- Update API documentation and CHANGELOG

BREAKING CHANGE: /admin/mails and /user_api/mails no longer accept keyword parameter

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

* fix: restore Mail ID query input in Index.vue

- Keep showMailIdQuery UI input for querying specific mail by ID
- Triggered when URL contains mail_id parameter

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>

worker/package.json

@@ -11,10 +11,10 @@
     "build": "wrangler deploy --dry-run --outdir dist --minify"
   },
   "devDependencies": {
-    "@cloudflare/workers-types": "^4.20251211.0",
+    "@cloudflare/workers-types": "^4.20251213.0",
     "@eslint/js": "9.39.1",
     "@simplewebauthn/types": "10.0.0",
-    "@types/node": "^25.0.0",
+    "@types/node": "^25.0.2",
     "eslint": "9.39.1",
     "globals": "^16.5.0",
     "typescript-eslint": "^8.49.0",
@@ -24,7 +24,7 @@
     "@aws-sdk/client-s3": "3.888.0",
     "@aws-sdk/s3-request-presigner": "3.888.0",
     "@simplewebauthn/server": "10.0.1",
-    "hono": "^4.10.8",
+    "hono": "^4.11.0",
     "jsonpath-plus": "^10.3.0",
     "mimetext": "^3.0.27",
     "postal-mime": "^2.6.1",