feat: add SurveyInvite model

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

backend/alembic/env.py

@@ -14,6 +14,8 @@ from app.models.email_verification_token import EmailVerificationToken
 from app.models.tree_embedding import TreeEmbedding
 from app.models.copilot_conversation import CopilotConversation
 from app.models.assistant_chat import AssistantChat
+from app.models.survey_response import SurveyResponse
+from app.models.survey_invite import SurveyInvite
 from app.core.config import settings
 
 # this is the Alembic Config object

backend/app/models/__init__.py

@@ -32,6 +32,8 @@ from .ai_chat_session import AIChatSession
 from .tree_embedding import TreeEmbedding
 from .copilot_conversation import CopilotConversation
 from .assistant_chat import AssistantChat
+from .survey_response import SurveyResponse
+from .survey_invite import SurveyInvite
 
 __all__ = [
     "User",
@@ -75,4 +77,6 @@ __all__ = [
     "TreeEmbedding",
     "CopilotConversation",
     "AssistantChat",
+    "SurveyResponse",
+    "SurveyInvite",
 ]

backend/app/models/survey_invite.py

@@ -0,0 +1,26 @@
+"""Survey invite tracking for FlowPilot research."""
+import secrets
+import uuid
+from datetime import datetime, timezone
+
+from sqlalchemy import Boolean, Column, DateTime, String
+from sqlalchemy.dialects.postgresql import UUID
+
+from app.core.database import Base
+
+
+def _generate_token() -> str:
+    return secrets.token_urlsafe(16)
+
+
+class SurveyInvite(Base):
+    __tablename__ = "survey_invites"
+
+    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
+    token = Column(String(32), unique=True, nullable=False, default=_generate_token)
+    recipient_name = Column(String(255), nullable=False)
+    recipient_email = Column(String(255), nullable=True)
+    status = Column(String(20), nullable=False, default="pending")
+    email_sent = Column(Boolean, nullable=False, default=False)
+    created_at = Column(DateTime(timezone=True), default=lambda: datetime.now(timezone.utc), nullable=False)
+    completed_at = Column(DateTime(timezone=True), nullable=True)