feat(admin): editable member email + Danish slug folding

Lets a fenja admin edit a member's email in the People resource (the
field was read-only). Email is required, format- and uniqueness-checked,
and normalised to lowercase on save; collisions surface as a form error
via the new updateUserEmail() helper.

Also folds ø/æ/å in slugifyName so Danish names produce clean member
slugs (soren-friis, not s-ren-friis) — NFKD leaves those letters intact.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/admin/resources/users.ts

@@ -15,6 +15,7 @@ import {
   getAllUsersPublic,
   getUserPublicById,
   updateUserAdminFields,
+  updateUserEmail,
   updateUserProfile,
   updateUserRole,
   deactivateUser,
@@ -217,7 +218,15 @@ export const usersResource: Resource<UserPublic> = {
           'Changing the role has real access consequences. Setting to Council also allocates a member number.',
       },
       { key: 'name', label: 'Name', kind: 'text', required: true, maxLength: 120 },
-      { key: 'email', label: 'Email', kind: 'text', readOnly: true },
+      {
+        key: 'email',
+        label: 'Email',
+        kind: 'text',
+        required: true,
+        maxLength: 200,
+        pattern: /^[^\s@]+@[^\s@]+\.[^\s@]+$/,
+        helperText: 'The member’s login identity. Normalised to lowercase on save; must be unique.',
+      },
       { key: 'organisation', label: 'Organisation', kind: 'text', readOnly: true,
         helperText: 'Set at sign-up; editing is not yet supported.' },
       { key: 'bio', label: 'Bio', kind: 'textarea', rows: 4 },
@@ -282,6 +291,13 @@ export const usersResource: Resource<UserPublic> = {
       const current = getUserPublicById(id);
       if (!current) throw new Error(`User ${id} not found`);
 
+      // Email (login identity) — only written when changed. Throws on a
+      // collision, which the save handler surfaces as a form error.
+      const newEmail = String(data.email ?? '').trim().toLowerCase();
+      if (newEmail && newEmail !== current.email) {
+        updateUserEmail(id, newEmail);
+      }
+
       // Profile fields (name + bio).
       const newName = String(data.name ?? current.name);
       const newBio = String(data.bio ?? current.bio ?? '');

src/lib/db.ts

@@ -152,6 +152,15 @@ export function updateUserProfile(id: number, name: string, bio: string): void {
   db.prepare('UPDATE users SET name = ?, bio = ? WHERE id = ?').run(name, bio, id);
 }
 
+/** Update a user's email — their login identity. Throws if the address is
+ *  already used by another account (the column is UNIQUE). */
+export function updateUserEmail(id: number, email: string): void {
+  const clash = db.prepare('SELECT id FROM users WHERE email = ? AND id != ?')
+    .get(email, id) as { id: number } | undefined;
+  if (clash) throw new Error('That email is already in use by another account.');
+  db.prepare('UPDATE users SET email = ? WHERE id = ?').run(email, id);
+}
+
 /** Returns the newly-allocated member_number when the transition lands on
  *  cab and the user had none; null otherwise. Callers may ignore. */
 export function updateUserRole(id: number, role: Role): { allocated: number | null } {
@@ -213,7 +222,8 @@ export function updateUserAdminFields(id: number, data: {
 export function slugifyName(name: string): string {
   return name
     .toLowerCase()
-    .normalize('NFKD').replace(/[̀-ͯ]/g, '') // strip diacritics
+    .replace(/ø/g, 'o').replace(/æ/g, 'ae').replace(/å/g, 'a') // Danish letters NFKD leaves intact
+    .normalize('NFKD').replace(/[̀-ͯ]/g, '') // strip remaining diacritics
     .replace(/[^a-z0-9]+/g, '-')
     .replace(/^-+|-+$/g, '');
 }