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/src/components/DriverForm.tsx

@@ -114,6 +114,7 @@ export function DriverForm({ driver, onSubmit, onCancel, isSubmitting }: DriverF
               <option value="">Select Department</option>
               <option value="OFFICE_OF_DEVELOPMENT">Office of Development</option>
               <option value="ADMIN">Admin</option>
+              <option value="OTHER">Other</option>
             </select>
           </div>