Add inline media previews for runs list and detail page

- Run card shows thumbnail previews for inputs and output
- Run detail shows output media inline (image/video/audio)
- Add audio detection (MP3, FLAC, OGG, WAV) to detect_media_type
- Add debug logging for recipe count on home page
- Add console.log debugging for DAG elements

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/services/run_service.py

@@ -50,7 +50,10 @@ def detect_media_type(cache_path: Path) -> str:
     # Video signatures
     if header[:4] == b'\x1a\x45\xdf\xa3':  # WebM/MKV
         return "video"
-    if len(header) > 8 and header[4:8] == b'ftyp':  # MP4/MOV
+    if len(header) > 8 and header[4:8] == b'ftyp':  # MP4/MOV/M4A
+        # Check for audio-only M4A
+        if len(header) > 11 and header[8:12] in (b'M4A ', b'm4a '):
+            return "audio"
         return "video"
     if header[:4] == b'RIFF' and len(header) > 12 and header[8:12] == b'AVI ':  # AVI
         return "video"
@@ -65,6 +68,16 @@ def detect_media_type(cache_path: Path) -> str:
     if header[:4] == b'RIFF' and len(header) > 12 and header[8:12] == b'WEBP':  # WebP
         return "image"
 
+    # Audio signatures
+    if header[:3] == b'ID3' or header[:2] == b'\xff\xfb':  # MP3
+        return "audio"
+    if header[:4] == b'fLaC':  # FLAC
+        return "audio"
+    if header[:4] == b'OggS':  # Ogg (could be audio or video, assume audio)
+        return "audio"
+    if header[:4] == b'RIFF' and len(header) > 12 and header[8:12] == b'WAVE':  # WAV
+        return "audio"
+
     return "unknown"