Add ESLint + Prettier + EditorConfig tooling at repo root

v1.0 Phase 1.1 — repo-wide lint/format baseline.

- eslint.config.mjs (flat config) lints server, client, shared
- .prettierrc.json, .prettierignore, .editorconfig, .nvmrc
- Root package.json holds shared devDeps; per-package scripts keep
  their typecheck + test runners
- Fix 7 lint issues surfaced by the baseline run:
  - TicketDetail.tsx: replace ternary-with-side-effects with if/else
  - admin/Users.tsx: escape apostrophe in JSX
  - errorHandler.ts: typed err as unknown with ErrorLike refinement
  - users.ts: Prisma.UserUpdateInput instead of Record<string, any>
  - seed.ts: drop unused goddard binding
- Run prettier across tracked sources for a clean formatting baseline

client/src/pages/Login.tsx

@@ -1,28 +1,28 @@
-import { useState } from 'react'
-import { useNavigate } from 'react-router-dom'
-import { useAuth } from '../contexts/AuthContext'
+import { useState } from 'react';
+import { useNavigate } from 'react-router-dom';
+import { useAuth } from '../contexts/AuthContext';
 
 export default function Login() {
-  const { login } = useAuth()
-  const navigate = useNavigate()
-  const [username, setUsername] = useState('')
-  const [password, setPassword] = useState('')
-  const [error, setError] = useState('')
-  const [loading, setLoading] = useState(false)
+  const { login } = useAuth();
+  const navigate = useNavigate();
+  const [username, setUsername] = useState('');
+  const [password, setPassword] = useState('');
+  const [error, setError] = useState('');
+  const [loading, setLoading] = useState(false);
 
   const handleSubmit = async (e: React.FormEvent) => {
-    e.preventDefault()
-    setError('')
-    setLoading(true)
+    e.preventDefault();
+    setError('');
+    setLoading(true);
     try {
-      await login(username, password)
-      navigate('/')
+      await login(username, password);
+      navigate('/');
     } catch {
-      setError('Invalid username or password')
+      setError('Invalid username or password');
     } finally {
-      setLoading(false)
+      setLoading(false);
     }
-  }
+  };
 
   return (
     <div className="min-h-screen bg-gray-950 flex items-center justify-center px-4">
@@ -43,9 +43,7 @@ export default function Login() {
           )}
 
           <div>
-            <label className="block text-sm font-medium text-gray-300 mb-1">
-              Username
-            </label>
+            <label className="block text-sm font-medium text-gray-300 mb-1">Username</label>
             <input
               type="text"
               value={username}
@@ -57,9 +55,7 @@ export default function Login() {
           </div>
 
           <div>
-            <label className="block text-sm font-medium text-gray-300 mb-1">
-              Password
-            </label>
+            <label className="block text-sm font-medium text-gray-300 mb-1">Password</label>
             <input
               type="password"
               value={password}
@@ -79,5 +75,5 @@ export default function Login() {
         </form>
       </div>
     </div>
-  )
+  );
 }