fix(extension): stop the video-state poll from restarting the target

getReadyTabVideoState() treated "no video found" as a broken injection and
forced a full reactivation. On a page that legitimately has no video yet — an
anime or Drive page before playback starts — that fired on every call, and the
dev panel polls it on a timer. The result was an endless teardown and
reinjection cycle: the target never settled, the popup showed "activating"
forever, and the panel reported "Target tab changed before content script
recovery completed" because each read raced the reactivation it had triggered.

Only an unreachable content script justifies recovery now, and that recovery no
longer reinjects unless the selected frame actually moved.

Audited against v3.1.2, which worked on these pages. The only unjustified
deviation left was the retry budget, which had been cut from eight passes to
three and shortened the window for a late-loading player; it is back at eight,
now bounded by a wall-clock deadline instead of being unbounded.

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

tests/e2e/extension.spec.mjs

@@ -674,6 +674,38 @@ test('selects an anime tab before playback and promotes the player once it appea
     expect(promoted).toMatchObject({ targetTabId: tabId, targetActivationState: 'ready' });
 });
 
+test('polling video state on a page with no video does not restart the target', async ({ context, extensionId, baseURL }) => {
+    // The dev panel polls GET_VIDEO_STATE on a timer. On an anime page the
+    // answer is legitimately "no video" until playback starts, and treating
+    // that as a broken injection reactivated the target on every poll — which
+    // is what pinned the popup on "activating" forever.
+    const url = `${baseURL}/pages/yummy-deferred-player.html`;
+    const page = await context.newPage();
+    await page.goto(url);
+    await page.waitForFunction(() => window.__fixtureReady === true);
+
+    const { tabId } = await selectTargetTab(context, extensionId, url);
+
+    for (let poll = 0; poll < 6; poll++) {
+        const state = await getExtensionState(context, extensionId, { type: 'GET_VIDEO_STATE', tabId });
+        expect(state?.error, 'reading video state must not report a target change').toBeFalsy();
+        expect(state).toMatchObject({ found: false });
+        const status = await getExtensionState(context, extensionId, { type: 'GET_STATUS' });
+        expect(status, `poll ${poll} must leave the target ready`).toMatchObject({
+            targetTabId: tabId,
+            targetReady: true,
+            targetActivationState: 'ready'
+        });
+    }
+
+    // And the player is still picked up once it exists.
+    const deferred = page.frames().find(frame => frame.url().endsWith('/frames/deferred-player-frame.html'));
+    await deferred.locator('#poster').click();
+    await expect
+        .poll(() => deferred.locator('video').getAttribute('data-koala-attached'), { timeout: 15000 })
+        .toBe('true');
+});
+
 test('keeps the tab selected when its activation fails', async ({ context, extensionId }) => {
     // A page the extension is not allowed to script stands in for any activation
     // failure the user can act on. Losing the selection here is what made the