Implement Workstream I: Account pages with code review fixes

Add account management UI with profile settings, authentication options,
device/passkey management, and session management pages.

Key changes:
- Add account pages: profile, auth, devices, sessions
- Add dialog components: confirm, add-passkey, change-password, rename-passkey
- Return passkeyId from verifyRegistration to fix race condition
- Add hasPassword field to user schema
- Add aria-label to dialog close button for accessibility
- Add avatar URL validation and fix phone input styling
- Add comprehensive test plan documentation

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docs/initial-app.md

@@ -2293,10 +2293,10 @@ _Depends on: D1-D9, E1-E4, C3_
 _Depends on: F1-F7, C3_
 _Can run parallel to H after F1 is done_
 
-- [ ] **I1**: Create `/account` page (profile settings, avatar upload)
-- [ ] **I2**: Create `/account/auth` page (password, passkeys management)
-- [ ] **I3**: Create `/account/devices` page (trusted devices)
-- [ ] **I4**: Create `/account/sessions` page (session history)
+- [x] **I1**: Create `/account` page (profile settings, avatar upload)
+- [x] **I2**: Create `/account/auth` page (password, passkeys management)
+- [x] **I3**: Create `/account/devices` page (trusted devices)
+- [x] **I4**: Create `/account/sessions` page (session history)
 
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