Add admin commands for database operations

Features:
- Add admin command group for database operations
- admin list-users: List all users from SQLite/PostgreSQL/MySQL
- admin user-notes: List notes for specific user
- Add CodiMDDatabase class for direct DB access

cli_anything/codimd/codimd_cli.py

@@ -122,6 +122,12 @@ def config():
     pass
 
 
+@cli.group()
+def admin():
+    """Admin operations (require database access)."""
+    pass
+
+
 # Note commands
 @note.command("list")
 @click.option("--limit", type=int, help="Limit number of results")
@@ -599,6 +605,109 @@ def config_set(key, value):
         click.echo(f"Set {key} = {value}")
 
 
+# Admin commands
+@admin.command("list-users")
+@click.option("--db-type", type=click.Choice(["sqlite", "postgresql", "mysql"]), default="sqlite", help="Database type")
+@click.option("--db-path", type=Path, help="SQLite database path")
+@click.option("--db-host", help="Database host (for PostgreSQL/MySQL)")
+@click.option("--db-name", help="Database name (for PostgreSQL/MySQL)")
+@click.option("--db-user", help="Database user (for PostgreSQL/MySQL)")
+@click.option("--db-password", help="Database password (for PostgreSQL/MySQL)")
+@click.option("--db-port", type=int, default=5432, help="Database port (default: 5432 for PostgreSQL, 3306 for MySQL)")
+@handle_error
+def admin_list_users(db_type, db_path, db_host, db_name, db_user, db_password, db_port):
+    """List all users in the CodiMD database."""
+    from cli_anything.codimd.core import CodiMDDatabase
+
+    if db_type == "sqlite":
+        if not db_path:
+            # Try default CodiMD SQLite path
+            default_paths = [
+                "./codimd/db.sqlite",
+                "./db.sqlite",
+                "/var/lib/codimd/db.sqlite"
+            ]
+            for path in default_paths:
+                if Path(path).exists():
+                    db_path = path
+                    break
+            if not db_path:
+                raise ValueError(
+                    "SQLite database path not found. "
+                    "Please specify with --db-path or ensure db.sqlite is in current directory."
+                )
+        users = CodiMDDatabase.list_users_sqlite(str(db_path))
+
+    elif db_type == "postgresql":
+        if not all([db_host, db_name, db_user]):
+            raise ValueError("--db-host, --db-name, and --db-user are required for PostgreSQL")
+        if not db_password:
+            db_password = click.prompt("Database password", hide_input=True)
+        users = CodiMDDatabase.list_users_postgresql(db_host, db_name, db_user, db_password, db_port)
+
+    elif db_type == "mysql":
+        if not all([db_host, db_name, db_user]):
+            raise ValueError("--db-host, --db-name, and --db-user are required for MySQL")
+        if not db_password:
+            db_password = click.prompt("Database password", hide_input=True)
+        users = CodiMDDatabase.list_users_mysql(db_host, db_name, db_user, db_password, db_port)
+
+    if ctx["json_mode"]:
+        output_json(format_success({"users": users, "count": len(users)}))
+    else:
+        if not users:
+            click.echo("No users found.")
+        else:
+            click.echo(f"Total users: {len(users)}")
+            for u in users:
+                user_id = u.get("id", "N/A")[:8] + "..." if len(u.get("id", "")) > 8 else u.get("id", "N/A")
+                email = u.get("email") or "N/A"
+
+                # Get name from profile
+                profile = u.get("profile")
+                if profile:
+                    if isinstance(profile, str):
+                        try:
+                            profile = json.loads(profile)
+                        except:
+                            profile = {}
+                    name = profile.get("name") or profile.get("displayName") or "N/A"
+                else:
+                    name = "N/A"
+
+                created = u.get("createdAt", "N/A")
+                click.echo(f"  {user_id} | {email:30s} | {name}")
+                if created != "N/A":
+                    click.echo(f"    Created: {created}")
+
+
+@admin.command("user-notes")
+@click.argument("user_id")
+@click.option("--db-path", type=Path, default="./db.sqlite", help="SQLite database path")
+@handle_error
+def admin_user_notes(user_id, db_path):
+    """List all notes for a specific user."""
+    from cli_anything.codimd.core import CodiMDDatabase
+
+    if not Path(db_path).exists():
+        raise FileNotFoundError(f"Database not found: {db_path}")
+
+    notes = CodiMDDatabase.list_user_notes_sqlite(str(db_path), user_id)
+
+    if ctx["json_mode"]:
+        output_json(format_success({"user_id": user_id, "notes": notes, "count": len(notes)}))
+    else:
+        if not notes:
+            click.echo(f"No notes found for user {user_id}")
+        else:
+            click.echo(f"Notes for user {user_id}: {len(notes)} total")
+            for n in notes:
+                note_id = n.get("shortid", n.get("id", "N/A"))
+                title = n.get("title") or "Untitled"
+                permission = n.get("permission", "N/A")
+                click.echo(f"  {note_id} | {title[:50]} | [{permission}]")
+
+
 # REPL mode
 @cli.command("repl")
 @handle_error