feat(e2e): Playwright suite — 134 tests across 9 spec areas + UA matrix

Adds an end-to-end Playwright test suite under e2e/ that spins up an
isolated docker-compose stack (Postgres :55432, Caddy :3101, backend with
EVENTSNAP_TEST_MODE=1, SvelteKit adapter-node frontend) and exercises the
SvelteKit app against the real Rust backend.

Phase 1 — happy paths covering every documented USER_JOURNEYS.md flow:
  01-auth/      join, recover, admin login, leave event, PIN lockout
  02-upload/    gallery picker (API path), rate-limit + admin toggle
  03-feed/      like/comment SSE, filters, SSE reconnect on visibility
  04-host/      event lock API, ban/unban, promote
  05-admin/     config validation, foundational authz guards, stats
  06-export/    /export status + download stub
  __smoke/      cross-UA happy-path (runs on every UA project)

Phase 2 — adversarial + browser chaos:
  07-adversarial/  XSS payloads (6 × display name path), SQLi shapes,
                   length / encoding / RTL override / NUL byte;
                   file-upload boundaries (ELF body claimed as JPEG,
                   oversize vs max_image_size_mb, zero-byte, NUL
                   filename, path-traversal, SVG-with-script);
                   JWT alg:none, signature/payload tamper, expired
                   session, PIN brute-force (serial + parallel),
                   admin password brute-force; deep authz (cross-user
                   delete, banned user across like/comment/feed-read,
                   host→admin escalation); small-scale DDoS (20× /join,
                   10MB comment body, 10 concurrent SSE).
  08-browser-chaos/ localStorage / sessionStorage / cookie purge,
                    IndexedDB drop mid-session, offline → reconnect,
                    slow-3G, 503 flakes, 429 with no retry storm,
                    multi-tab same/different user, no-JS, hostile CSS,
                    clock skew ±1h / -2d, localStorage quota exhausted.

Phase 3 — mobile gestures (runs only on chromium-mobile / Pixel 7):
  09-mobile/    touch-target ≥44px audit, env(safe-area-inset-bottom)
                structural check, long-press (FeedListCard → ContextSheet,
                quick-tap negation, click-suppression), double-tap
                (feed card like + lightbox heart-burst, via synthetic
                pointer events to bypass the first-tap-fires-click trap),
                viewport reflow (portrait/landscape/narrow/phablet),
                plus fixme stubs documenting planned gestures (swipe
                lightbox L/R, swipe-down dismiss, pull-to-refresh,
                long-press-comment).

Cross-UA matrix (chromium-engine projects run @smoke only):
  chromium-pixel7, chromium-galaxy-s22, samsung-internet (Samsung UA
  emulation on Galaxy viewport), edge-android, plus webkit-iphone,
  chrome-ios, firefox-android, firefox-desktop — the latter four need
  libavif16 on the host (Playwright dep) but the configs are in place.

Infrastructure:
  - fixtures/test.ts central test.extend (api, db, adminToken, guest,
    host, signIn). Per-test DB truncate via the dev-only POST
    /admin/__truncate route, gated by EVENTSNAP_TEST_MODE=1.
  - helpers/sse-listener.ts, helpers/upload-client.ts (Node-side
    multipart for adversarial file-upload tests + JPEG/PNG/ELF magic
    constants), helpers/touch.ts (longPress / doubleTap / swipe /
    inlineStyle / computedStyle).
  - 10 page objects covering every route + UploadSheet/Lightbox.
  - global-setup waits for /health, logs in admin, disables every
    rate-limit and quota toggle.
  - .github/workflows/e2e.yml: PR check runs chromium-desktop + the
    smoke matrix in parallel, uploads playwright-report/ and traces on
    failure.

Findings the suite surfaces as live `[finding]` warnings (not silenced):
  1. /admin/login has no rate-limit or lockout (bcrypt cost only).
  2. PIN-attempt counter races under parallel /recover requests.
  3. Zero-byte uploads pass /api/v1/upload.
  4. SVG-with-script can pass the magic-byte check (consider CSP +
     X-Content-Type-Options on /media/*).

Stack-internal docs live in e2e/README.md (UA tier table, Samsung
Internet escalation tiers A/B/C, debugging tips, roadmap).

Final tally: 134 passed / 0 failed / 9 skipped (test.fixme stubs for
not-yet-shipped gestures and one UI-upload-flow investigation).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

e2e/specs/09-mobile/gestures-longpress.spec.ts

@@ -0,0 +1,93 @@
+/**
+ * Phase 3 mobile — long-press gesture.
+ *
+ * The `longpress` action attaches to `<article>` in FeedListCard and to
+ * grid cells in FeedGrid. Holding for ≥ 500 ms fires `onlongpress`,
+ * which opens the ContextSheet bottom sheet via the feed page's
+ * `contextTarget` state.
+ *
+ * Setup needs at least one upload to render a card. We post via the
+ * Phase 2 upload-client helper, then drive the gesture with the touch
+ * helper.
+ */
+import { test, expect } from '../../fixtures/test';
+import { uploadRaw, JPEG_MAGIC } from '../../helpers/upload-client';
+import { longPress } from '../../helpers/touch';
+import { readFileSync } from 'node:fs';
+import { join } from 'node:path';
+
+const SAMPLE_JPG = join(process.cwd(), 'fixtures', 'media', 'sample.jpg');
+
+async function seedUpload(token: string, caption = 'Longpress fixture') {
+  const body = readFileSync(SAMPLE_JPG);
+  const res = await uploadRaw(token, body, {
+    filename: 'lp.jpg',
+    contentType: 'image/jpeg',
+    caption,
+  });
+  if (res.status !== 201) {
+    const text = await res.text();
+    throw new Error(`Upload seed failed (${res.status}): ${text}`);
+  }
+  return res.json() as Promise<{ id: string }>;
+}
+
+test.describe('Mobile — long-press gesture', () => {
+  test('long-press on a FeedListCard opens the ContextSheet', async ({ page, guest, signIn }) => {
+    const g = await guest('Lp1');
+    await seedUpload(g.jwt, 'Hold to open');
+    await signIn(page, g);
+    await page.goto('/feed');
+
+    // Wait for at least one article to render. Caption text appears once feed loads.
+    const card = page.locator('article').filter({ hasText: g.displayName }).first();
+    await expect(card).toBeVisible({ timeout: 10_000 });
+
+    await longPress(page, card, 600);
+
+    // The ContextSheet renders a dialog with role="dialog" + aria-modal="true".
+    // Multiple sheets (UploadSheet, ContextSheet) may be in the DOM — match the
+    // one that actually has aria-modal=true (i.e. the open one).
+    // ContextSheet is always mounted (it just translates off-screen when closed).
+    // Match the OPEN state by the `translate-y-0` class the component applies
+    // when `open === true`.
+    const sheet = page.locator('[role="dialog"][aria-modal="true"].translate-y-0');
+    await expect(sheet).toBeVisible({ timeout: 2_000 });
+    await expect(sheet.getByRole('button', { name: /abbrechen/i })).toBeVisible();
+  });
+
+  test('a quick tap (< 500 ms) does NOT open the ContextSheet — only opens the lightbox', async ({ page, guest, signIn }) => {
+    const g = await guest('Lp2');
+    await seedUpload(g.jwt, 'Quick tap');
+    await signIn(page, g);
+    await page.goto('/feed');
+
+    const card = page.locator('article').filter({ hasText: g.displayName }).first();
+    await expect(card).toBeVisible({ timeout: 10_000 });
+
+    // Simulate a short press (200 ms — well under the 500 ms threshold).
+    await longPress(page, card, 200);
+
+    // Within 1 s, no aria-modal=true dialog should be open (the ContextSheet
+    // is "open" only when its aria-modal flag is true).
+    // The ContextSheet stays mounted but `translate-y-0` is only set when open.
+    await expect(page.locator('[role="dialog"][aria-modal="true"].translate-y-0')).toHaveCount(0, { timeout: 1_000 });
+  });
+
+  test('long-press suppresses the click that lands at pointerup (no double-open of lightbox)', async ({ page, guest, signIn }) => {
+    const g = await guest('Lp3');
+    await seedUpload(g.jwt, 'Suppress click');
+    await signIn(page, g);
+    await page.goto('/feed');
+
+    const card = page.locator('article').filter({ hasText: g.displayName }).first();
+    await expect(card).toBeVisible({ timeout: 10_000 });
+
+    await longPress(page, card, 700);
+
+    // The longpress action sets `suppressNextClick = true` — so the lightbox
+    // (separate role=dialog) should NOT appear in addition to the context sheet.
+    // Exactly one aria-modal=true dialog should be open: the context sheet.
+    await expect(page.locator('[role="dialog"][aria-modal="true"]')).toHaveCount(1, { timeout: 2_000 });
+  });
+});