Implement Phase 2: Refresh tokens, 2FA, password reset, and audit logging

Co-authored-by: mblanke <9078342+mblanke@users.noreply.github.com>

backend/app/models/audit_log.py

@@ -0,0 +1,24 @@
+from sqlalchemy import Column, Integer, String, DateTime, ForeignKey, Text, JSON
+from sqlalchemy.orm import relationship
+from datetime import datetime, timezone
+
+from app.core.database import Base
+
+
+class AuditLog(Base):
+    __tablename__ = "audit_logs"
+
+    id = Column(Integer, primary_key=True, index=True)
+    user_id = Column(Integer, ForeignKey("users.id"), nullable=True)
+    tenant_id = Column(Integer, ForeignKey("tenants.id"), nullable=False)
+    action = Column(String, nullable=False)  # CREATE, READ, UPDATE, DELETE
+    resource_type = Column(String, nullable=False)  # user, host, case, etc.
+    resource_id = Column(Integer, nullable=True)
+    details = Column(JSON, nullable=True)
+    ip_address = Column(String, nullable=True)
+    user_agent = Column(String, nullable=True)
+    created_at = Column(DateTime, default=lambda: datetime.now(timezone.utc), index=True)
+
+    # Relationships
+    user = relationship("User")
+    tenant = relationship("Tenant")