fix: harden frame observation and unblock supported Drive tabs

Audit follow-ups on the same-origin frame walk:
- prune detached frames from the load-hook set so ad/SPA frame churn
  no longer grows it for the page's lifetime
- hook load on nested frames, not just top-level ones
- re-observe from scratch after a frame reload instead of leaving the
  replaced document's tree registered
- reset the frame registry when the heartbeat error path disconnects

Also: a broad parent domain in the blacklist no longer hides a host with
its own supported player path (drive.google.com behind google.com), while
an exact user entry for that host still filters it.

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

extension/content.js

@@ -1697,23 +1697,37 @@
 
     }
 
-
+
+
     // --- Helper: Wait until video is ready for playback (buffered & seeked) ---
 
     function pollSeekReady(targetTime, timeoutMs = 8000) {
         return new Promise((resolve) => {
             const interval = 150;
-            const interval = 150;
-            let elapsed = 0;
-            const timer = setInterval(() => {
-                if (destroyed) {
+            let elapsed = 0;
+            const timer = setInterval(() => {
+                if (destroyed) {
+                    clearInterval(timer);
+                    seekPollTimers.delete(timer);
+                    resolve(false);
+                    return;
+                }
+                const video = findVideo(); // Re-query DOM on every iteration
+                if (!video) {
+                    clearInterval(timer);
+                    seekPollTimers.delete(timer);
+                    resolve(false);
                     return;
                 }
 
 
 
-                const video = findVideo(); // Re-query DOM on every iteration
+                elapsed += interval;
+
+                const current = getSyncCurrentTime(video);
+                const timeDiff = current !== null ? Math.abs(current - targetTime) : Infinity;
                 const ready = video.readyState >= 3 && timeDiff < 2.0;
+                if (ready) {
                     clearInterval(timer);
                     seekPollTimers.delete(timer);
                     resolve(true);
@@ -1764,6 +1778,7 @@
 
 
         if (message.action === 'RESET_AUDIO_PROCESSING') {
+
             _audioProcessingAllowed = false;
 
             bypassCurrentAudioProcessing();