feat(a11y): form input labels (H-6), remaining button labels (C-1)

H-6: aria-label on all form inputs missing accessible names:
  - Login: username, password (already done)
  - Register: username, password, confirm, token, email
  - Password reset: email, new password, confirm password
  - Settings: display name, user ID to ignore, keyword, page zoom,
    date format, device name, backup passwords (new/confirm/restore)
  - Auth: server URL picker input
C-1: additional icon buttons:
  - RoomInput: toolbar toggle (aria-pressed + label)
  - Lobby/Members: scroll to top, toggle member list
  - UIAFlowOverlay: cancel authentication
  - BackupRestore: backup options menu
  - UrlPreview: previous/next preview buttons
  - RoomPacks: undo remove/remove pack buttons
  - RoomViewHeader: start call, member list toggle
  - ServerPicker: change server button

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

src/app/pages/auth/reset-password/PasswordResetForm.tsx

@@ -177,6 +177,7 @@ export function PasswordResetForm({ defaultEmail }: PasswordResetFormProps) {
           defaultValue={defaultEmail}
           type="email"
           name="emailInput"
+          aria-label="Email address"
           variant="Background"
           size="500"
           required
@@ -199,6 +200,7 @@ export function PasswordResetForm({ defaultEmail }: PasswordResetFormProps) {
                 ref={passRef}
                 onChange={doMatch}
                 name="passwordInput"
+                aria-label="New password"
                 variant="Background"
                 size="500"
                 outlined
@@ -213,6 +215,7 @@ export function PasswordResetForm({ defaultEmail }: PasswordResetFormProps) {
                 ref={confPassRef}
                 onChange={doMatch}
                 name="confirmPasswordInput"
+                aria-label="Confirm new password"
                 variant="Background"
                 size="500"
                 style={{ color: match ? undefined : color.Critical.Main }}