test(actions): add defaultPrevented coverage for clickOutside (#195)

The action already checks event.defaultPrevented before dispatching
clickoutside, but that branch had no test. Add the missing case and
add a one-line comment explaining why capture phase is used.

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

frontend/src/lib/actions/clickOutside.svelte.spec.ts

@@ -51,6 +51,18 @@ describe('clickOutside action', () => {
 		expect(fired).toBe(false);
 	});
 
+	it('does not dispatch clickoutside when event.defaultPrevented is true', () => {
+		const node = makeNode();
+		const outside = makeNode();
+		let fired = false;
+		node.addEventListener('clickoutside', () => (fired = true));
+		clickOutside(node);
+		const event = new MouseEvent('click', { bubbles: true, cancelable: true });
+		event.preventDefault();
+		outside.dispatchEvent(event);
+		expect(fired).toBe(false);
+	});
+
 	it('removes the listener on destroy', () => {
 		const node = makeNode();
 		const outside = makeNode();

frontend/src/lib/actions/clickOutside.ts

@@ -5,6 +5,7 @@ export function clickOutside(node: HTMLElement): { destroy: () => void } {
 		}
 	}
 
+	// Capture phase (true) ensures this fires before any child stopPropagation() calls.
 	document.addEventListener('click', handleClick, true);
 
 	return {