refactor(B1): migrate to domain-driven project structure

Move all models/schemas/services/routers into app/domains/.
Keep backward-compat shims in old locations for imports.
Preserves domains/rendering/tasks.py from Phase A.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/app/domains/rendering/models.py

@@ -0,0 +1,81 @@
+import uuid
+from datetime import datetime
+from sqlalchemy import String, DateTime, Boolean, Text, Integer, Float, ForeignKey
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+from sqlalchemy.dialects.postgresql import UUID, JSONB
+from app.database import Base
+
+VALID_RENDER_BACKENDS = {"celery"}
+
+
+class OutputType(Base):
+    __tablename__ = "output_types"
+
+    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
+    name: Mapped[str] = mapped_column(String(200), unique=True, nullable=False)
+    description: Mapped[str | None] = mapped_column(Text, nullable=True)
+    renderer: Mapped[str] = mapped_column(String(50), nullable=False, default="threejs")
+    render_settings: Mapped[dict] = mapped_column(JSONB, nullable=False, default=dict)
+    output_format: Mapped[str] = mapped_column(String(20), nullable=False, default="png")
+    sort_order: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
+    compatible_categories: Mapped[list] = mapped_column(JSONB, default=list, server_default="[]")
+    render_backend: Mapped[str] = mapped_column(String(20), nullable=False, default="auto", server_default="auto")
+    is_animation: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False, server_default="false")
+    transparent_bg: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False, server_default="false")
+    cycles_device: Mapped[str | None] = mapped_column(String(10), nullable=True, default=None)
+    pricing_tier_id: Mapped[int | None] = mapped_column(
+        Integer, ForeignKey("pricing_tiers.id", ondelete="SET NULL"), nullable=True, index=True
+    )
+    is_active: Mapped[bool] = mapped_column(Boolean, nullable=False, default=True)
+    created_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow, nullable=False)
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime, default=datetime.utcnow, onupdate=datetime.utcnow, nullable=False
+    )
+
+    order_lines: Mapped[list["OrderLine"]] = relationship("OrderLine", back_populates="output_type")
+    pricing_tier: Mapped["PricingTier | None"] = relationship("PricingTier", back_populates="output_types")
+
+
+class RenderTemplate(Base):
+    __tablename__ = "render_templates"
+
+    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
+    name: Mapped[str] = mapped_column(String(300), nullable=False)
+    category_key: Mapped[str | None] = mapped_column(String(100), nullable=True)
+    output_type_id: Mapped[uuid.UUID | None] = mapped_column(
+        UUID(as_uuid=True), ForeignKey("output_types.id", ondelete="SET NULL"), nullable=True
+    )
+    blend_file_path: Mapped[str] = mapped_column(Text, nullable=False)
+    original_filename: Mapped[str] = mapped_column(String(500), nullable=False)
+    target_collection: Mapped[str] = mapped_column(String(200), nullable=False, default="Product", server_default="Product")
+    material_replace_enabled: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False, server_default="false")
+    lighting_only: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False, server_default="false")
+    shadow_catcher_enabled: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False, server_default="false")
+    camera_orbit: Mapped[bool] = mapped_column(Boolean, nullable=False, default=True, server_default="true")
+    is_active: Mapped[bool] = mapped_column(Boolean, nullable=False, default=True, server_default="true")
+    created_at: Mapped[datetime] = mapped_column(DateTime, nullable=False, server_default="now()")
+    updated_at: Mapped[datetime] = mapped_column(DateTime, nullable=False, server_default="now()", onupdate=datetime.utcnow)
+
+    output_type = relationship("OutputType", lazy="joined")
+
+
+class ProductRenderPosition(Base):
+    __tablename__ = "product_render_positions"
+
+    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
+    product_id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True), ForeignKey("products.id", ondelete="CASCADE"), nullable=False, index=True
+    )
+    name: Mapped[str] = mapped_column(String(200), nullable=False)
+    rotation_x: Mapped[float] = mapped_column(Float, nullable=False, default=0.0)
+    rotation_y: Mapped[float] = mapped_column(Float, nullable=False, default=0.0)
+    rotation_z: Mapped[float] = mapped_column(Float, nullable=False, default=0.0)
+    is_default: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False)
+    sort_order: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
+    created_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow, nullable=False)
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime, default=datetime.utcnow, onupdate=datetime.utcnow, nullable=False
+    )
+
+    product: Mapped["Product"] = relationship("Product", back_populates="render_positions")
+    order_lines: Mapped[list["OrderLine"]] = relationship("OrderLine", back_populates="render_position")