fix(parental-lock): tell Enter in the PIN field from a click on Save

Moving on to an empty repeat was decided by document.activeElement in
submit(). WebKit does not focus a clicked button, so a click on Save
with the PIN field focused looked like Enter: focus moved and no error
showed. The advance is now a keydown.enter handler on the PIN field
that prevents the submission, and submit() refuses an empty repeat on
every path.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/electron-backend-e2e/src/parental-lock-pin-dialog.e2e.ts

@@ -110,7 +110,16 @@ test.describe('Electron parental-lock PIN dialog', () => {
                 'new-password'
             );
 
+            // Enter after the PIN moves on to the empty repeat; Save
+            // with the repeat still empty is refused.
             await pin.fill(PIN);
+            await pin.press('Enter');
+            await expect(confirm).toBeFocused();
+            await expect(mismatch).toBeHidden();
+            await submit.click();
+            await expect(mismatch).toBeVisible();
+            await expect(dialog).toBeVisible();
+
             await confirm.fill(PIN.slice(0, 3));
             await expect(mismatch).toBeHidden();
             await expect(confirm).toHaveAttribute('aria-invalid', 'false');

docs/architecture/parental-lock.md

@@ -429,7 +429,8 @@ so a cancelled or refused PIN leaves it showing the real state.
   disabled default button; `submit()` refuses instead, shakes the field
   (no shake under `prefers-reduced-motion: reduce`) and focuses it — except
   that Enter in the PIN field with the repeat still empty only moves focus
-  to the repeat. Set
+  to the repeat (a `keydown.enter` handler: focus cannot tell Enter from a
+  click on Save, since WebKit does not focus a clicked button). Set
   mode marks both inputs `autocomplete="new-password"`. The Electron
   `parental-lock-pin-dialog.e2e.ts` covers the labels and the
   mismatch → fix → save flow.

libs/ui/components/src/lib/parental-lock-pin-dialog/parental-lock-pin-dialog.component.html

@@ -26,6 +26,7 @@
                 [errorStateMatcher]="pinErrorState"
                 [ngModel]="pin()"
                 (ngModelChange)="onPinInput($event)"
+                (keydown.enter)="onPinEnter($event)"
                 name="pin"
             />
             <mat-hint>

libs/ui/components/src/lib/parental-lock-pin-dialog/parental-lock-pin-dialog.component.spec.ts

@@ -171,16 +171,37 @@ describe('ParentalLockPinDialogComponent', () => {
 
         it('moves on to an empty repeat on Enter in the PIN field', async () => {
             const dialog = await openDialog({ mode: 'set' });
+            const enter = new KeyboardEvent('keydown', {
+                key: 'Enter',
+                cancelable: true,
+            });
 
             await dialog.type('parental-lock-pin', '2468');
-            dialog.query('parental-lock-pin')?.focus();
-            await dialog.pressEnter();
+            dialog.query('parental-lock-pin')?.dispatchEvent(enter);
+            await dialog.fixture.whenStable();
 
+            // Handled before the form sees it: no implicit submission.
+            expect(enter.defaultPrevented).toBe(true);
             expect(document.activeElement).toBe(
                 dialog.query('parental-lock-pin-confirm')
             );
             expect(dialog.query('parental-lock-pin-mismatch')).toBeNull();
             expect(dialog.component.shake()).toBeNull();
+        });
+
+        it('refuses an empty repeat on Save while the PIN field keeps focus', async () => {
+            // WebKit does not focus a clicked button, so focus says nothing
+            // about how the form was submitted.
+            const dialog = await openDialog({ mode: 'set' });
+
+            await dialog.type('parental-lock-pin', '2468');
+            dialog.query('parental-lock-pin')?.focus();
+            await dialog.pressEnter();
+
+            expect(text(dialog.query('parental-lock-pin-mismatch'))).toBe(
+                KEYS.mismatch
+            );
+            expect(dialog.component.shake()).toBe('confirmation');
             expect(dialog.close).not.toHaveBeenCalled();
         });
 

libs/ui/components/src/lib/parental-lock-pin-dialog/parental-lock-pin-dialog.component.ts

@@ -186,6 +186,23 @@ export class ParentalLockPinDialogComponent {
         this.clearRefusal('confirmation');
     }
 
+    /**
+     * Set mode: Enter after a complete first PIN moves on to an empty repeat
+     * instead of submitting. Handled on the key, not in `submit()`: focus
+     * cannot tell Enter from a click on Save, as WebKit does not focus a
+     * clicked button.
+     */
+    onPinEnter(event: Event): void {
+        if (
+            this.isSetMode() &&
+            !this.confirmation() &&
+            isValidParentalLockPin(this.pin())
+        ) {
+            event.preventDefault();
+            this.confirmationInput()?.nativeElement.focus();
+        }
+    }
+
     async submit(): Promise<void> {
         if (this.busy() || this.inCooldown()) {
             return;
@@ -197,12 +214,6 @@ export class ParentalLockPinDialogComponent {
             return;
         }
         if (this.isSetMode()) {
-            const pinField = this.pinInput()?.nativeElement;
-            if (!this.confirmation() && document.activeElement === pinField) {
-                // Enter after the first PIN moves on to the repeat.
-                this.confirmationInput()?.nativeElement.focus();
-                return;
-            }
             if (this.confirmation() !== pin) {
                 this.refuse('confirmation');
                 return;