fix(cover): E2兜底封面标题样式透传color/position/font_size (#1467)

apps/api/app/api/routes/generation_cover.py

@@ -63,7 +63,15 @@ class GenerateCoverResponse(BaseModel):
 # ── Route ────────────────────────────────────────────────────────────────
 
 
-def _persist_cover_frame(frame_url: str, plan_id: str, title_text: str = "") -> str:
+def _persist_cover_frame(
+    frame_url: str,
+    plan_id: str,
+    title_text: str = "",
+    *,
+    title_color: str = "#ffffff",
+    title_position: str = "bottom",
+    title_font_size: int | None = None,
+) -> str:
     """下载 MediaKit 返回的临时帧图，可选叠加标题后转存到 OSS covers/ 路径。
 
     Args:
@@ -71,6 +79,9 @@ def _persist_cover_frame(frame_url: str, plan_id: str, title_text: str = "") ->
         plan_id: 剪辑计划 ID（生成 OSS key）
         title_text: 非空时用 Pillow 在帧上叠加标题（用于 E2 从源素材抽帧，
             因为源素材本身没有烧录标题）
+        title_color: 标题字体颜色（#RRGGBB）
+        title_position: 标题位置 top/center/bottom
+        title_font_size: 标题字号，None 时自动计算
     """
     import tempfile
     import uuid
@@ -94,7 +105,13 @@ def _persist_cover_frame(frame_url: str, plan_id: str, title_text: str = "") ->
             try:
                 from packages.shared.title_overlay import apply_title_to_image
 
-                applied = apply_title_to_image(tmp_path, title_text)
+                applied = apply_title_to_image(
+                    tmp_path,
+                    title_text,
+                    color=title_color,
+                    position=title_position,
+                    font_size=title_font_size,
+                )
                 if applied:
                     logger.info("[封面生成] E2 帧图已叠加标题: plan_id=%s", plan_id)
             except Exception:
@@ -418,11 +435,15 @@ def generate_cover(
             asset_repo = SQLAlchemyAssetRepository(db)
             storage_svc = get_shared_storage_service()
             mk_client = get_mediakit_client()
-            # 从 plan.config 读取标题，E2 从源素材抽帧时叠加（源素材本身无标题）
+            # 从 plan.config 读取完整标题样式，E2 从源素材抽帧时叠加（源素材本身无标题）
             _e2_title_cfg = (plan.config or {}).get("title", {}) or {}
             if not isinstance(_e2_title_cfg, dict):
                 _e2_title_cfg = {}
             _e2_title_text = (_e2_title_cfg.get("text", "") or "").strip() if _e2_title_cfg.get("enabled", True) else ""
+            # 读取标题样式：前端可能传 color 或 font_color，都兼容
+            _e2_title_color = _e2_title_cfg.get("color") or _e2_title_cfg.get("font_color") or "#ffffff"
+            _e2_title_position = _e2_title_cfg.get("position", "bottom") or "bottom"
+            _e2_title_font_size = _e2_title_cfg.get("font_size") or _e2_title_cfg.get("size")
             if mk_client.is_available:
                 for aid in body.asset_ids:
                     try:
@@ -452,7 +473,14 @@ def generate_cover(
                         if snapshots:
                             raw = snapshots[0].get("image_url") or snapshots[0].get("url") or ""
                             if raw:
-                                cover_url_from_task = _persist_cover_frame(raw, plan_id, title_text=_e2_title_text)
+                                cover_url_from_task = _persist_cover_frame(
+                                    raw,
+                                    plan_id,
+                                    title_text=_e2_title_text,
+                                    title_color=_e2_title_color,
+                                    title_position=_e2_title_position,
+                                    title_font_size=_e2_title_font_size,
+                                )
                                 logger.info(
                                     "[封面生成] 统一管道封面(步骤E-source-asset): plan_id=%s url=%s",
                                     plan_id,