Phase 3 Complete: Python API Foundation (T027-T038)

Completed all Python API infrastructure tasks:

✅ Core Application (T027-T029):
- FastAPI app with CORS, error handling, structured logging
- Pydantic Settings for environment configuration
- SQLAlchemy async engine with connection pooling
- Alembic migration environment

✅ Infrastructure Clients (T030-T032):
- Redis async client with connection pooling
- gRPC SDK Bridge client (placeholder for protobuf generation)
- Alembic migration environment configured

✅ Utilities & Middleware (T033-T035):
- JWT utilities: create, decode, verify tokens (access & refresh)
- Error translation: gRPC status codes → HTTP status codes
- Error handler middleware for consistent error responses

✅ Database Models (T036-T038):
- User model with RBAC (viewer, operator, administrator)
- AuditLog model for tracking all operations
- Initial migration: creates users and audit_logs tables
- Default admin user (username: admin, password: admin123)

Features:
- Async/await throughout
- Type hints with Pydantic
- Structured JSON logging
- Connection pooling (DB, Redis, gRPC)
- Environment-based configuration
- Permission hierarchy system

Ready for Phase 4: Authentication Implementation

🤖 Generated with Claude Code

src/api/models/user.py

@@ -0,0 +1,65 @@
+"""
+User model for authentication and authorization
+"""
+from sqlalchemy import Column, String, DateTime, Enum as SQLEnum
+from sqlalchemy.dialects.postgresql import UUID
+from datetime import datetime
+import uuid
+import enum
+from models import Base
+
+class UserRole(str, enum.Enum):
+    """User roles for RBAC"""
+    VIEWER = "viewer"          # Read-only: view cameras, monitors, routing state
+    OPERATOR = "operator"      # Viewer + execute cross-switch, clear monitors
+    ADMINISTRATOR = "administrator"  # Full access: all operator + user management, config
+
+class User(Base):
+    """User model for authentication"""
+    __tablename__ = "users"
+
+    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
+    username = Column(String(50), unique=True, nullable=False, index=True)
+    password_hash = Column(String(255), nullable=False)
+    role = Column(SQLEnum(UserRole), nullable=False, default=UserRole.VIEWER)
+    created_at = Column(DateTime, default=datetime.utcnow, nullable=False)
+    updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow, nullable=False)
+
+    def __repr__(self):
+        return f"<User(id={self.id}, username={self.username}, role={self.role})>"
+
+    def has_permission(self, required_role: UserRole) -> bool:
+        """
+        Check if user has required permission level
+
+        Permission hierarchy:
+        ADMINISTRATOR > OPERATOR > VIEWER
+        """
+        role_hierarchy = {
+            UserRole.VIEWER: 1,
+            UserRole.OPERATOR: 2,
+            UserRole.ADMINISTRATOR: 3
+        }
+
+        user_level = role_hierarchy.get(self.role, 0)
+        required_level = role_hierarchy.get(required_role, 0)
+
+        return user_level >= required_level
+
+    def can_execute_crossswitch(self) -> bool:
+        """Check if user can execute cross-switch operations"""
+        return self.has_permission(UserRole.OPERATOR)
+
+    def can_manage_users(self) -> bool:
+        """Check if user can manage other users"""
+        return self.role == UserRole.ADMINISTRATOR
+
+    def to_dict(self):
+        """Convert to dictionary (exclude password_hash)"""
+        return {
+            "id": str(self.id),
+            "username": self.username,
+            "role": self.role.value,
+            "created_at": self.created_at.isoformat(),
+            "updated_at": self.updated_at.isoformat()
+        }