feat: add feedback database model and migration

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

backend/app/models/feedback.py

@@ -0,0 +1,19 @@
+import uuid
+from datetime import datetime, timezone
+from typing import Optional
+from sqlalchemy import String, Text, DateTime, ForeignKey
+from sqlalchemy.orm import Mapped, mapped_column
+from sqlalchemy.dialects.postgresql import UUID
+from app.core.database import Base
+
+
+class Feedback(Base):
+    __tablename__ = "feedback"
+
+    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
+    account_id: Mapped[Optional[uuid.UUID]] = mapped_column(UUID(as_uuid=True), ForeignKey("accounts.id", ondelete="SET NULL"), nullable=True)
+    user_id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), ForeignKey("users.id", ondelete="SET NULL"), nullable=False)
+    email: Mapped[str] = mapped_column(String(255), nullable=False)
+    feedback_type: Mapped[str] = mapped_column(String(50), nullable=False)
+    message: Mapped[str] = mapped_column(Text, nullable=False)
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=lambda: datetime.now(timezone.utc))