feat(#2039): add viral video DB models + alembic migration

- viral_video_jobs: 爆款视频任务主表（含 v1.3 reference_video/style_strength/style_guide 字段）
- viral_video_style_templates: 风格模板配置（seed 4 个系统模板）
- viral_video_prompt_templates: Prompt 模板（由 #2040 seed，7 种 prompt_type）
- 单元测试 4 个，覆盖三表 CRUD 与默认值

packages/adapters/sqlalchemy_impl/models.py

@@ -918,3 +918,71 @@ class GpuWorkerModel(Base):
     capabilities = Column(String(500), nullable=False, default="")  # 逗号分隔，如 "musetalk"
     last_heartbeat_at = Column(DateTime, nullable=True, index=True)
     created_at = Column(DateTime, nullable=False, default=lambda: datetime.now(UTC))
+
+
+class ViralVideoJobModel(Base):
+    """爆款视频任务"""
+
+    __tablename__ = "viral_video_jobs"
+
+    id = Column(String(36), primary_key=True)
+    user_id = Column(String(36), nullable=False, index=True)
+    images = Column(JSON, nullable=False, default=list)  # 产品图片 URL 列表
+    industry = Column(String(100), nullable=False, default="")
+    target_customer = Column(String(500), nullable=False, default="")
+    persona_id = Column(String(36), nullable=False, default="")
+    viral_structure = Column(String(50), nullable=False, default="")
+    marketing_purpose = Column(String(100), nullable=False, default="")
+    bgm_preference = Column(String(50), nullable=False, default="")
+    duration = Column(Integer, nullable=False, default=30)
+    user_copy_text = Column(Text, nullable=False, default="")
+    fusion_level = Column(String(20), nullable=False, default="ai_polish")
+    reference_audio_path = Column(String(1000), nullable=False, default="")
+    # v1.3 新增字段
+    reference_video_url = Column(String(1000), nullable=False, default="")
+    style_strength = Column(String(20), nullable=False, default="medium")
+    style_guide = Column(JSON, nullable=True)
+    style_template_id = Column(String(36), nullable=False, default="", index=True)
+    # 结果与状态
+    status = Column(String(30), nullable=False, default="pending", index=True)
+    intent_result = Column(JSON, nullable=True)
+    result_video_url = Column(String(1000), nullable=False, default="")
+    credits_cost = Column(Integer, nullable=False, default=0)
+    error_msg = Column(Text, nullable=False, default="")
+    retry_count = Column(Integer, nullable=False, default=0)
+    started_at = Column(DateTime(timezone=True), nullable=True)
+    completed_at = Column(DateTime(timezone=True), nullable=True)
+    created_at = Column(DateTime(timezone=True), nullable=False, default=lambda: datetime.now(UTC))
+    updated_at = Column(DateTime(timezone=True), nullable=False, default=lambda: datetime.now(UTC))
+
+
+class ViralVideoStyleTemplateModel(Base):
+    """爆款视频风格模板配置表"""
+
+    __tablename__ = "viral_video_style_templates"
+
+    id = Column(String(36), primary_key=True)
+    name = Column(String(200), nullable=False)
+    description = Column(Text, nullable=False, default="")
+    thumbnail_url = Column(String(1000), nullable=False, default="")
+    style_config = Column(JSON, nullable=False, default=dict)
+    is_system = Column(Boolean, nullable=False, default=True, index=True)
+    sort_order = Column(Integer, nullable=False, default=0)
+    created_at = Column(DateTime(timezone=True), nullable=False, default=lambda: datetime.now(UTC))
+    updated_at = Column(DateTime(timezone=True), nullable=False, default=lambda: datetime.now(UTC))
+
+
+class ViralVideoPromptTemplateModel(Base):
+    """爆款视频 Prompt 模板表（由 #2040 seed）"""
+
+    __tablename__ = "viral_video_prompt_templates"
+
+    id = Column(String(36), primary_key=True)
+    prompt_type = Column(String(50), nullable=False, index=True)
+    name = Column(String(200), nullable=False)
+    content = Column(Text, nullable=False, default="")
+    variables = Column(JSON, nullable=False, default=list)
+    version = Column(Integer, nullable=False, default=1)
+    is_active = Column(Boolean, nullable=False, default=True, index=True)
+    created_at = Column(DateTime(timezone=True), nullable=False, default=lambda: datetime.now(UTC))
+    updated_at = Column(DateTime(timezone=True), nullable=False, default=lambda: datetime.now(UTC))