very nice

cht/window.py

@@ -60,6 +60,7 @@ class ChtWindow(Adw.ApplicationWindow):
             on_transcript_ready=lambda segs: self._transcript_panel.add_items(segs),
             on_scene_marker=lambda ts: self._timeline.add_scene_marker(ts),
             on_recorder_restarted=lambda path: self._monitor.set_recording(path),
+            on_manifest_updated=lambda: self._update_scrub_bar_manifest(),
         )
 
         # Panels (own their selection state)
@@ -252,20 +253,33 @@ class ChtWindow(Adw.ApplicationWindow):
         log.info("Waiting for sender...")
 
     def _on_live_toggle(self):
-        pos = self._monitor.get_live_position()
-        self._timeline.toggle_live(live_player_pos=pos)
+        if self._timeline.state.live:
+            # Live → Scrub: don't load growing MKV, let user pick a segment
+            self._timeline.toggle_live(live_player_pos=self._monitor.get_live_position())
+            # Refresh manifest so scrub bar shows completed segments
+            self._update_scrub_bar_manifest()
+        else:
+            # Scrub → Live: restore recording path and resume
+            mgr = self._lifecycle.stream_mgr
+            if mgr:
+                self._monitor.set_recording(mgr.recording_path)
+            self._timeline.toggle_live()
 
     # -- Scrub --
 
     def _update_scrub_bar_manifest(self):
-        """Refresh the scrub bar with the current session's segment manifest."""
+        """Refresh the scrub bar with the current session's segment manifest and frames."""
         mgr = self._lifecycle.stream_mgr
         if not mgr:
             return
         self._manifest = load_segment_manifest(mgr.session_dir)
         if not self._manifest:
             self._manifest = rebuild_manifest(mgr.session_dir)
-        self._timeline_controls.scrub_bar.set_manifest(self._manifest)
+        scrub_bar = self._timeline_controls.scrub_bar
+        scrub_bar.set_manifest(self._manifest)
+        # Feed frame thumbnails to the scrub bar
+        frames = load_frame_index(mgr.frames_dir)
+        scrub_bar.set_frames([{"timestamp": f["timestamp"], "path": str(f["path"])} for f in frames])
 
     def _on_segment_activated(self, scrub_bar, segment_index):
         """User clicked a segment block — request its proxy."""
@@ -327,12 +341,16 @@ class ChtWindow(Adw.ApplicationWindow):
     def _scrub_tick(self):
         """Release throttle so next scrub motion can update monitor."""
         self._scrub_pending = False
+        cursor = self._timeline.state.cursor
         # Apply latest cursor position to monitor
-        seg, local_time = global_time_to_segment(
-            self._manifest, self._timeline.state.cursor
-        )
+        seg, local_time = global_time_to_segment(self._manifest, cursor)
         if seg:
             self._monitor.scrub_to(local_time)
+        # Sync waveform, time labels, etc. at throttled rate
+        self._timeline.emit("changed")
+        # Highlight nearest frame/transcript
+        self._frames_panel.highlight_nearest(cursor)
+        self._transcript_panel.highlight_nearest(cursor)
         return False
 
     def _capture_at_scrub_position(self):
@@ -583,6 +601,10 @@ class ChtWindow(Adw.ApplicationWindow):
             self._frames_panel.load_items(items)
             self._known_frames = {item["id"] for item in items}
             self._agent_output.append(f"  Loaded {len(items)} frame thumbnails.\n")
+            # Update scrub bar thumbnails
+            self._timeline_controls.scrub_bar.set_frames(
+                [{"timestamp": e["timestamp"], "path": str(e["path"])} for e in entries]
+            )
 
     def _load_existing_transcript(self):
         if not self._lifecycle.stream_mgr:
@@ -608,6 +630,7 @@ class ChtWindow(Adw.ApplicationWindow):
                 pixbuf = GdkPixbuf.Pixbuf.new_from_file_at_scale(str(entry["path"]), 256, 144, True)
                 auto = not self._transcript_panel.has_selection
                 self._frames_panel.add_item(fid, pixbuf, entry["timestamp"], auto_select=auto)
+                self._timeline_controls.scrub_bar.add_frame(entry["timestamp"], str(entry["path"]))
             except Exception as e:
                 log.warning("Thumbnail load failed for %s: %s", fid, e)
         return True