feat(billing): add sales_leads and stripe_events tables

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

backend/app/models/sales_lead.py

@@ -0,0 +1,28 @@
+import uuid
+from datetime import datetime, timezone
+from typing import Optional
+from sqlalchemy import String, DateTime, Text, Index
+from sqlalchemy.orm import Mapped, mapped_column
+from sqlalchemy.dialects.postgresql import UUID
+from app.core.database import Base
+
+
+class SalesLead(Base):
+    __tablename__ = "sales_leads"
+    __table_args__ = (Index("ix_sales_leads_email", "email"),)
+
+    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
+    email: Mapped[str] = mapped_column(String(255), nullable=False)
+    name: Mapped[str] = mapped_column(String(255), nullable=False)
+    company: Mapped[str] = mapped_column(String(255), nullable=False)
+    team_size: Mapped[Optional[str]] = mapped_column(String(20), nullable=True)
+    message: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
+    source: Mapped[str] = mapped_column(String(50), nullable=False)
+    posthog_distinct_id: Mapped[Optional[str]] = mapped_column(String(255), nullable=True)
+    status: Mapped[str] = mapped_column(String(20), nullable=False, default="new")
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=lambda: datetime.now(timezone.utc))
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True),
+        default=lambda: datetime.now(timezone.utc),
+        onupdate=lambda: datetime.now(timezone.utc),
+    )