feat: user profile customization with banner, accent color, bio, and full profile modal

Add banner image, accent color, and bio fields to user profiles with
full-stack support: schema migration, API validation (hex color format,
190-char bio limit), sanitizeUser propagation, and new GET /users/:id/mutuals
endpoint. Rewrite AccountPanel with live preview card, avatar/banner upload
via ImageCropModal, 16-preset accent color picker, and bio editor. Enhance
UserProfilePopout with banner display, accent-colored names, bio rendering,
and mutual counts. Add new UserProfileModal with About/Mutual Friends/Mutual
Spaces tabs and friend action buttons.

packages/web/src/components/chat/FriendsPage.test.tsx

@@ -48,6 +48,9 @@ const makeFriend = (overrides: Partial<TaggedFriend> = {}): TaggedFriend => ({
   username: 'testfriend',
   displayName: 'Test Friend',
   avatar: null,
+  banner: null,
+  accentColor: null,
+  bio: null,
   status: 'online',
   customStatus: null,
   createdAt: Date.now(),
@@ -70,6 +73,9 @@ const makeRequest = (overrides: Partial<TaggedFriendRequest> = {}): TaggedFriend
     username: 'otheruser',
     displayName: 'Other User',
     avatar: null,
+    banner: null,
+    accentColor: null,
+    bio: null,
     status: 'online',
     customStatus: null,
     isAdmin: false,
@@ -227,6 +233,9 @@ describe('FriendsPage', () => {
           username: 'recipient',
           displayName: 'Recipient',
           avatar: null,
+          banner: null,
+          accentColor: null,
+          bio: null,
           status: 'online',
           customStatus: null,
           isAdmin: false,
@@ -275,6 +284,9 @@ describe('FriendsPage', () => {
           username: 'sender',
           displayName: 'Sender',
           avatar: null,
+          banner: null,
+          accentColor: null,
+          bio: null,
           status: 'online',
           customStatus: null,
           isAdmin: false,
@@ -318,6 +330,9 @@ describe('FriendsPage', () => {
           username: 'sender2',
           displayName: 'Sender 2',
           avatar: null,
+          banner: null,
+          accentColor: null,
+          bio: null,
           status: 'online',
           customStatus: null,
           isAdmin: false,