Clarify Windows vs Clawdbot responsibilities

Windows KB Capture now:
- Records clips
- Merges video
- Transcribes with Whisper (GPU)
- Finds screenshot triggers with context
- Exports: merged.mp4, transcript.json, metadata.json

Clawdbot (via knowledge-base skill) now:
- Extracts frames at trigger timestamps
- Vision analyzes frames
- Updates KB files
- Organizes images

Removed frame extraction from Windows - that's Mario's job.
Added screenshot_triggers to metadata.json with context for Mario.

src/cad_documenter/export.py

@@ -64,18 +64,14 @@ class SessionExporter:
         self.on_progress("Merging clips...", 0.1)
         merged_path = self._merge_clips(session_dir, kept_clips, export_dir)
         
-        # Step 2: Transcribe
+        # Step 2: Transcribe (uses local GPU Whisper)
         self.on_progress("Transcribing audio...", 0.3)
         transcript = self._transcribe(merged_path, export_dir)
         
-        # Step 3: Extract frames at screenshot triggers
-        self.on_progress("Extracting frames...", 0.7)
-        frames_dir = export_dir / "frames"
-        self._extract_frames(merged_path, transcript, frames_dir)
-        
-        # Step 4: Create metadata
-        self.on_progress("Creating metadata...", 0.9)
-        self._create_metadata(session, export_dir, merged_path)
+        # Step 3: Create metadata
+        # Note: Frame extraction is done by Clawdbot using the knowledge-base skill
+        self.on_progress("Creating metadata...", 0.8)
+        self._create_metadata(session, export_dir, merged_path, transcript)
         
         self.on_progress("Export complete!", 1.0)
         
@@ -230,13 +226,43 @@ class SessionExporter:
         secs = int(seconds % 60)
         return f"{mins:02d}-{secs:02d}"
     
+    def _find_screenshot_triggers(self, transcript: dict) -> list[dict]:
+        """Find 'screenshot' triggers in transcript with context."""
+        triggers = []
+        segments = transcript.get("segments", [])
+        
+        for i, segment in enumerate(segments):
+            text = segment.get("text", "").lower()
+            if "screenshot" in text:
+                timestamp = segment.get("start", 0)
+                
+                # Get context: 2 segments before and after
+                context_segments = segments[max(0, i-2):i+3]
+                context = " ".join(s.get("text", "") for s in context_segments)
+                
+                triggers.append({
+                    "timestamp": timestamp,
+                    "timestamp_formatted": self._format_timestamp(timestamp),
+                    "segment_text": segment.get("text", ""),
+                    "context": context.strip(),
+                })
+        
+        return triggers
+    
     def _create_metadata(
         self,
         session: Session,
         export_dir: Path,
         merged_path: Path,
+        transcript: dict,
     ) -> None:
         """Create metadata.json for Clawdbot."""
+        # Find screenshot triggers for Mario
+        triggers = self._find_screenshot_triggers(transcript)
+        
+        # Get video duration
+        duration = self._get_video_duration(merged_path)
+        
         metadata = {
             "session_id": session.id,
             "name": session.name,
@@ -245,7 +271,8 @@ class SessionExporter:
             "created_at": session.created_at.isoformat(),
             "exported_at": datetime.now().isoformat(),
             "clip_count": session.clip_count,
-            "total_duration": session.total_duration,
+            "total_duration": duration,
+            "status": "pending",  # → "processed" after Clawdbot processes
             "clips": [
                 {
                     "id": clip.id,
@@ -254,10 +281,10 @@ class SessionExporter:
                 }
                 for clip in session.kept_clips
             ],
+            "screenshot_triggers": triggers,  # Pre-parsed for Mario
             "files": {
                 "video": "merged.mp4",
                 "transcript": "transcript.json",
-                "frames": "frames/",
             },
         }