feat: 剪辑计划编辑器后端 — 模板 CRUD + 分类 + 生成校验

- domain: Template, TemplateSegment, TemplateCategory 实体
- ports: TemplateRepositoryPort Protocol
- adapters: SQLAlchemyTemplateRepository + 3 个 ORM Model
- application: CRUD use cases + GenerateFromTemplateUseCase
- 业务规则: one_take=1片段, voice_over_mix=每段需material_type, 配音±30%警告
- schemas: Pydantic request/response models
- routes: /api/v1/templates CRUD + /generate + /categories
- alembic: 014_add_template_tables (templates/template_segments/template_categories)
- tests: 21 个单元测试全部通过

packages/adapters/sqlalchemy_impl/models.py

@@ -280,3 +280,43 @@ class RecipeItemModel(Base):
     position = Column(Integer, nullable=False, default=0)
     extra_meta = Column('metadata', JSON, nullable=False, default=dict)
 
+
+class TemplateModel(Base):
+    __tablename__ = "templates"
+
+    id = Column(String(36), primary_key=True)
+    user_id = Column(String(36), nullable=False, index=True)
+    name = Column(String(200), nullable=False)
+    mode = Column(String(30), nullable=False, index=True)  # pip / person_narration / one_take / voice_over_mix
+    category = Column(String(100), nullable=False, default="")
+    tags = Column(JSON, nullable=False, default=list)
+    title_config = Column(JSON, nullable=False, default=dict)
+    subtitle_config = Column(JSON, nullable=False, default=dict)
+    bgm_config = Column(JSON, nullable=False, default=dict)
+    estimated_duration = Column(Float, nullable=False, default=0.0)
+    is_active = Column(Boolean, nullable=False, default=True)
+    created_at = Column(DateTime, nullable=False, default=lambda: datetime.now(timezone.utc))
+    updated_at = Column(DateTime, nullable=False, default=lambda: datetime.now(timezone.utc))
+
+
+class TemplateSegmentModel(Base):
+    __tablename__ = "template_segments"
+
+    id = Column(String(36), primary_key=True)
+    template_id = Column(String(36), nullable=False, index=True)
+    segment_order = Column(Integer, nullable=False)
+    duration_min = Column(Float, nullable=False)
+    duration_max = Column(Float, nullable=False)
+    material_type = Column(String(20), nullable=True)  # 仅 voice_over_mix: 人物/场景
+    created_at = Column(DateTime, nullable=False, default=lambda: datetime.now(timezone.utc))
+    updated_at = Column(DateTime, nullable=False, default=lambda: datetime.now(timezone.utc))
+
+
+class TemplateCategoryModel(Base):
+    __tablename__ = "template_categories"
+
+    id = Column(String(36), primary_key=True)
+    user_id = Column(String(36), nullable=False, index=True)
+    name = Column(String(100), nullable=False)
+    created_at = Column(DateTime, nullable=False, default=lambda: datetime.now(timezone.utc))
+