fix: blocked autoplay left 'Loading…' parked over unreachable controls

The overlay only clears on 'playing', which never fires when the browser
blocks autoplay — and the overlay covers the native controls, so the
'swap to the native play button' assumption from the click-to-play
removal never held. A rejected v.play() is the signal: swap the dead
Loading… overlay for a tappable one (Play), and a second rejection
escalates to the Playback failed overlay.

Browser test fakes the policy (reject first gesture-less play()) since
headless Chromium allows autoplay. Logs showed the shape of it: six
loads of the same ep, 38-40 segments each, all 200, player never started.

tests/test_browser.py

@@ -278,3 +278,50 @@ async def _episode_watch_state():
         await page.wait_for_selector("#eps .ep.nextup", timeout=10000)
         assert not errors, errors
         await browser.close()
+
+
+
+
+def test_autoplay_blocked_shows_tap_to_play():
+    asyncio.run(_autoplay_blocked())
+
+
+async def _autoplay_blocked():
+    # Simulates the browser's autoplay policy (headless Chromium here allows
+    # autoplay, so the policy is faked): the first, gesture-less play()
+    # rejects; a later user-initiated one goes through. Regression: the
+    # "Loading…" overlay (which only clears on 'playing') used to sit over
+    # the unreachable native controls forever in that state.
+    async with async_playwright() as p:
+        browser = await p.chromium.launch()
+        context = await browser.new_context()
+        await context.add_init_script("""
+            const origPlay = HTMLMediaElement.prototype.play;
+            HTMLMediaElement.prototype.play = function () {
+                if (window.__firstPlayBlocked) {
+                    window.__firstPlayBlocked = false;
+                    return Promise.reject(new DOMException('blocked', 'NotAllowedError'));
+                }
+                return origPlay.call(this);
+            };
+            window.__firstPlayBlocked = true;
+        """)
+        page = await context.new_page()
+        errors = []
+        page.on("pageerror", lambda e: errors.append(str(e)))
+
+        await _login(page, "admin", "adminpw12345")
+        await page.goto(BASE + "/?anime=chainsaw-man-922")
+        await page.wait_for_selector("#eps .ep", timeout=30000)
+        # blocked autoplay: the dead "Loading…" must become a tappable overlay
+        await page.wait_for_function(
+            "document.querySelector('.pl-overlay') && "
+            "document.querySelector('.pl-overlay').textContent.includes('Tap to play')",
+            timeout=15000, polling=POLL)
+        # tapping (the gesture) starts real playback
+        await page.click(".pl-overlay .btn", force=True)
+        await page.wait_for_function(
+            "document.querySelector('video').currentTime > 0.5",
+            timeout=120000, polling=250)
+        assert not errors, errors
+        await browser.close()