feat(api): Pydantic schemas + Data Repositories

app/repositories/user.py

@@ -0,0 +1,63 @@
+"""User repository for database operations."""
+
+from uuid import UUID
+
+import asyncpg
+
+
+class UserRepository:
+    """Database operations for users."""
+
+    def __init__(self, conn: asyncpg.Connection) -> None:
+        self.conn = conn
+
+    async def create(
+        self,
+        user_id: UUID,
+        email: str,
+        password_hash: str,
+    ) -> dict:
+        """Create a new user."""
+        row = await self.conn.fetchrow(
+            """
+            INSERT INTO users (id, email, password_hash)
+            VALUES ($1, $2, $3)
+            RETURNING id, email, created_at
+            """,
+            user_id,
+            email,
+            password_hash,
+        )
+        return dict(row)
+
+    async def get_by_id(self, user_id: UUID) -> dict | None:
+        """Get user by ID."""
+        row = await self.conn.fetchrow(
+            """
+            SELECT id, email, password_hash, created_at
+            FROM users
+            WHERE id = $1
+            """,
+            user_id,
+        )
+        return dict(row) if row else None
+
+    async def get_by_email(self, email: str) -> dict | None:
+        """Get user by email."""
+        row = await self.conn.fetchrow(
+            """
+            SELECT id, email, password_hash, created_at
+            FROM users
+            WHERE email = $1
+            """,
+            email,
+        )
+        return dict(row) if row else None
+
+    async def exists_by_email(self, email: str) -> bool:
+        """Check if user exists by email."""
+        result = await self.conn.fetchval(
+            "SELECT EXISTS(SELECT 1 FROM users WHERE email = $1)",
+            email,
+        )
+        return result