Implement Issue #1: User Accounts & Profiles

- Admin-only account creation (no self-registration); invite-token flow
  replaces the public /auth/register endpoint
- New volunteer fields: phone, is_trainee, operational_roles,
  notification_preference, admin_notes, last_login, completed_shifts
- Role-scoped profile editing: volunteers update name/phone only;
  admins update all fields including notes and trainee flag
- /auth/activate endpoint for invite-token-based account activation
- /api/v1/volunteers/{id}/invite for admin to resend invite links
- last_login recorded on each successful authentication

Tests:
- Go: handler tests (auth rules, create, activate, update scoping) via
  Storer/AuthServicer interfaces and fake store; auth unit tests for
  HashPassword, IssueToken, and Parse
- Frontend: RTL tests for Activate, Profile, and Volunteers pages
- Fixed CRA 5 + React Router v7 Jest compatibility (moduleNameMapper +
  TextEncoder polyfill)
- Replaced stale CRA App.test.tsx placeholder with real tests

CI:
- .gitea/workflows/ci.yml runs go vet, go test, tsc, and npm test on
  every push and pull request

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

web/src/pages/Profile.tsx

@@ -0,0 +1,77 @@
+import React, { useEffect, useState, FormEvent } from 'react';
+import { api, Volunteer } from '../api';
+import { useAuth } from '../auth';
+
+export default function Profile() {
+  const { volunteerID } = useAuth();
+  const [volunteer, setVolunteer] = useState<Volunteer | null>(null);
+  const [name, setName] = useState('');
+  const [phone, setPhone] = useState('');
+  const [error, setError] = useState('');
+  const [success, setSuccess] = useState('');
+  const [saving, setSaving] = useState(false);
+
+  useEffect(() => {
+    if (!volunteerID) return;
+    api.getVolunteer(volunteerID).then(v => {
+      const vol = v as Volunteer;
+      setVolunteer(vol);
+      setName(vol.name);
+      setPhone(vol.phone ?? '');
+    }).catch(() => setError('Could not load profile.'));
+  }, [volunteerID]);
+
+  async function handleSubmit(e: FormEvent) {
+    e.preventDefault();
+    setError('');
+    setSuccess('');
+    if (!volunteerID) return;
+    setSaving(true);
+    try {
+      const updated = await api.updateVolunteer(volunteerID, { name, phone: phone || undefined });
+      setVolunteer(updated);
+      setSuccess('Profile updated.');
+    } catch (err: any) {
+      setError(err.message);
+    } finally {
+      setSaving(false);
+    }
+  }
+
+  if (!volunteer) return <div className="page"><p>Loading…</p></div>;
+
+  return (
+    <div className="page">
+      <h2>My Profile</h2>
+      {error && <p className="error">{error}</p>}
+      {success && <p className="success">{success}</p>}
+      <form onSubmit={handleSubmit} style={{ maxWidth: 400 }}>
+        <label>
+          Full name
+          <input value={name} onChange={e => setName(e.target.value)} required />
+        </label>
+        <label>
+          Email
+          <input value={volunteer.email} disabled />
+        </label>
+        <label>
+          Phone
+          <input value={phone} onChange={e => setPhone(e.target.value)} placeholder="Optional" />
+        </label>
+        <label>
+          Operational roles
+          <input value={volunteer.operational_roles || '—'} disabled />
+        </label>
+        <label>
+          Notification preference
+          <input value={volunteer.notification_preference} disabled />
+        </label>
+        <p style={{ color: '#666', fontSize: '0.85em' }}>
+          Completed shifts: {volunteer.completed_shifts}
+          {volunteer.is_trainee && ' · Trainee'}
+        </p>
+        <button type="submit" disabled={saving}>{saving ? 'Saving…' : 'Save Changes'}</button>
+      </form>
+    </div>
+  );
+}