added users administration tool

app/db_users.py

@@ -0,0 +1,73 @@
+# db_users.py
+import sqlite3
+from contextlib import contextmanager
+from typing import Optional
+import bcrypt
+
+DB_PATH = "app.db"
+
+@contextmanager
+def get_conn():
+    conn = sqlite3.connect(DB_PATH, check_same_thread=False)
+    conn.row_factory = sqlite3.Row
+    try:
+        yield conn
+        conn.commit()
+    finally:
+        conn.close()
+
+def init_db():
+    with get_conn() as conn:
+        conn.execute("""
+        CREATE TABLE IF NOT EXISTS users (
+            id INTEGER PRIMARY KEY AUTOINCREMENT,
+            username TEXT NOT NULL UNIQUE,
+            display_name TEXT,
+            email TEXT,
+            password_hash BLOB NOT NULL,
+            role TEXT NOT NULL DEFAULT 'user',
+            is_active INTEGER NOT NULL DEFAULT 1,
+            created_at TEXT NOT NULL DEFAULT (datetime('now'))
+        )
+        """)
+
+def list_users():
+    with get_conn() as conn:
+        rows = conn.execute("""
+            SELECT id, username, display_name, email, role, is_active, created_at
+            FROM users ORDER BY id
+        """).fetchall()
+        return [dict(r) for r in rows]
+
+def get_user(user_id: int) -> Optional[dict]:
+    with get_conn() as conn:
+        r = conn.execute("""
+            SELECT id, username, display_name, email, role, is_active
+            FROM users WHERE id = ?
+        """, (user_id,)).fetchone()
+        return dict(r) if r else None
+
+def create_user(username: str, password: str, display_name: str = "", email: str = "", role: str = "user", is_active: bool = True):
+    pw_hash = bcrypt.hashpw(password.encode("utf-8"), bcrypt.gensalt())
+    with get_conn() as conn:
+        conn.execute("""
+            INSERT INTO users (username, display_name, email, password_hash, role, is_active)
+            VALUES (?, ?, ?, ?, ?, ?)
+        """, (username, display_name, email, pw_hash, role, 1 if is_active else 0))
+
+def update_user(user_id: int, display_name: str, email: str, role: str, is_active: bool):
+    with get_conn() as conn:
+        conn.execute("""
+            UPDATE users
+            SET display_name=?, email=?, role=?, is_active=?
+            WHERE id=?
+        """, (display_name, email, role, 1 if is_active else 0, user_id))
+
+def set_password(user_id: int, new_password: str):
+    pw_hash = bcrypt.hashpw(new_password.encode("utf-8"), bcrypt.gensalt())
+    with get_conn() as conn:
+        conn.execute("UPDATE users SET password_hash=? WHERE id=?", (pw_hash, user_id))
+
+def delete_user(user_id: int):
+    with get_conn() as conn:
+        conn.execute("DELETE FROM users WHERE id=?", (user_id,))