fix(viral-video): fix 6 E2E bugs — fusion_level alias, concat silent segments, ingest lookup, duplicated URL, TTS voice/format, Seedance first-frame ratio

Bug1 (P0): schema accepts 'full_ai' as alias for 'ai_full' (Pydantic field_validator normalizes)
Bug2 (P0): concat_video_files probes each segment audio stream; Seedance gen_audio=False
       segments now marked has_audio=False so concat filter uses aevalsrc silence instead
       of failing with ffmpeg exit 234
Bug3 (P1): find_by_storage_key now queries (storage_key OR file_url) to cover historical
       data where the legacy file_url column held assets/<project>/<date>/... paths
Bug4 (P1): duplicated-hit response no longer accesses non-existent domain Asset.file_url;
       new helper _get_existing_asset_url uses storage_key (fallback file_url) through
       storage_service.get_url()
Bug5 (P1): _step_tts passes job.persona_id as voice_id (default longxiaochun_v3) and
       forces format='mp3' so downstream ffmpeg -map 1:a:0 works regardless of provider
Bug6 (P1): call_video_generation omits ratio param in first-frame (image_url) mode;
       ai_client.video_generation ratio becomes Optional[str] and is omitted from payload
       when None, fixing 400 InvalidParameter from Seedance

apps/worker/video_processing/concat_engine.py

@@ -553,7 +553,20 @@ def concat_video_files(
     if work_dir is None:
         work_dir = output_path.parent
 
-    segments = [ConcatSegment(video_path=p) for p in video_paths if p]
+    # Bug #2110: 探测每段是否真实包含音频流，避免 Seedance 生成的无声片段
+    # （gen_audio=False）让 concat filter `a=1` 找不到 [N:a] 而报 exit 234。
+    from video_processing.ffmpeg_utils import probe_has_audio as _probe_has_audio
+
+    segments: list[ConcatSegment] = []
+    for p in video_paths:
+        if not p:
+            continue
+        try:
+            has_audio = _probe_has_audio(p)
+        except Exception:
+            has_audio = True  # 探测失败保守认为有音频
+        segments.append(ConcatSegment(video_path=p, has_audio=has_audio))
+
     config = ConcatConfig(segments=segments, force_reencode=force_reencode)
 
     engine = ConcatEngine(work_dir)