feat(tasks): snooze — park a task at the bottom until a time

Snooze puts a task out of the way without finishing it or filing it: it sinks to
the bottom of its list and greys, and comes back on its own when its time passes.
No job wakes it — "snoozed" is just snoozed_until being still in the future, read
against the clock each time the list is ordered.

- `snoozed_until` on tasks (migration 0031); the list order sinks a still-snoozed
  task below everything, and it rejoins its place the moment the time passes.
- POST /tasks/{id}/snooze {until} — an RFC3339 time to snooze to, or empty to wake.
  Nothing else about the task moves; a snooze is about when you want to see it, not
  when it is due.
- The task drawer gains quick picks (this evening / tomorrow / next week) and a
  custom time, and a Wake now once it is snoozed. The row dims and carries a
  "snoozed until X" mark, and the list keeps snoozed tasks at the foot — the client
  sorts the same way the server does, so a drag-sorted list does not jump on reload.

Tests: snooze sinks a task below one made after it and waking returns it (Go); and
from the drawer the row greys, shows the mark, and un-greys on wake (e2e). Full
suites green.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

web/e2e/smoke.spec.js

@@ -127,6 +127,32 @@ test('hvert link i sidebjælken fører et sted hen', async ({ page }) => {
 	expect(trouble).toEqual([]);
 });
 
+test('en opgave kan slumres og hentes frem igen', async ({ page }) => {
+	const trouble = watchForTrouble(page);
+	await page.goto('/');
+
+	// "i dag" is parsed as the due date, so the task is named "Alfa" and shows here.
+	const box = page.getByLabel('Ny opgave');
+	await box.fill('Alfa i dag');
+	await box.press('Enter');
+
+	// Snooze it to tomorrow from its drawer.
+	await page.getByText('Alfa', { exact: true }).click();
+	const drawer = page.getByRole('complementary', { name: 'Opgave' });
+	await drawer.getByRole('button', { name: 'I morgen' }).click();
+
+	// The row greys — it carries the snoozed class and a "slumret til" mark.
+	const alfa = page.locator('.row', { hasText: 'Alfa' });
+	await expect(alfa).toHaveClass(/snoozed/);
+	await expect(alfa.locator('.snooze-mark')).toBeVisible();
+
+	// The drawer now offers to wake it, and waking takes the grey off.
+	await drawer.getByRole('button', { name: 'Væk nu' }).click();
+	await expect(alfa).not.toHaveClass(/snoozed/);
+
+	expect(trouble).toEqual([]);
+});
+
 test('en opgave kan åbnes og redigeres', async ({ page }) => {
 	const trouble = watchForTrouble(page);
 	await page.goto('/');