feat: add Help page with search, streamline copilot, misc UI fixes

Adds searchable Help/User Guide page, trims copilot tool bloat,
adds OTHER department option, and various form/layout improvements.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/package-lock.json

@@ -16,6 +16,7 @@
         "axios": "^1.6.5",
         "clsx": "^2.1.0",
         "date-fns": "^3.2.0",
+        "fuse.js": "^7.1.0",
         "leaflet": "^1.9.4",
         "lucide-react": "^0.309.0",
         "qrcode.react": "^4.2.0",
@@ -3442,6 +3443,15 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
+    "node_modules/fuse.js": {
+      "version": "7.1.0",
+      "resolved": "https://registry.npmjs.org/fuse.js/-/fuse.js-7.1.0.tgz",
+      "integrity": "sha512-trLf4SzuuUxfusZADLINj+dE8clK1frKdmqiJNb1Es75fmI5oY6X2mxLVUciLLjxqw/xr72Dhy+lER6dGd02FQ==",
+      "license": "Apache-2.0",
+      "engines": {
+        "node": ">=10"
+      }
+    },
     "node_modules/gensync": {
       "version": "1.0.0-beta.2",
       "resolved": "https://registry.npmjs.org/gensync/-/gensync-1.0.0-beta.2.tgz",