feat(scripts): add database query helpers for development

Add dbquery.py for MariaDB and sqlitequery.py for SQLite databases
in MCP service containers. Both scripts wrap docker compose exec to
simplify database inspection during development.

- dbquery.py: Query Nextcloud MariaDB with vertical/JSON output
- sqlitequery.py: Query MCP service SQLite DBs with service aliases
  (mcp, oauth, keycloak, basic) and column/JSON output modes
- Document both scripts in CLAUDE.md Database Inspection section

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

scripts/dbquery.py

@@ -0,0 +1,145 @@
+#!/usr/bin/env python3
+"""
+Database query helper for development.
+
+Wraps `docker compose exec db mariadb` to execute SQL statements against
+the Nextcloud MariaDB database.
+
+Usage:
+    ./scripts/dbquery.py "SELECT * FROM oc_notes LIMIT 5"
+    ./scripts/dbquery.py -u root -p password "SHOW TABLES"
+    ./scripts/dbquery.py --json "SELECT * FROM oc_oidc_clients"
+"""
+
+import argparse
+import subprocess
+import sys
+from pathlib import Path
+
+
+def find_compose_dir() -> Path:
+    """Find the directory containing docker-compose.yml."""
+    current = Path(__file__).resolve().parent
+    while current != current.parent:
+        if (current / "docker-compose.yml").exists():
+            return current
+        if (current / "compose.yml").exists():
+            return current
+        current = current.parent
+    # Default to script's parent directory
+    return Path(__file__).resolve().parent.parent
+
+
+def run_query(
+    sql: str,
+    user: str = "root",
+    password: str = "password",
+    database: str = "nextcloud",
+    vertical: bool = False,
+    json_output: bool = False,
+) -> tuple[int, str, str]:
+    """
+    Execute SQL via docker compose exec.
+
+    Returns:
+        Tuple of (return_code, stdout, stderr)
+    """
+    compose_dir = find_compose_dir()
+
+    cmd = [
+        "docker",
+        "compose",
+        "exec",
+        "-T",  # Disable pseudo-TTY allocation
+        "db",
+        "mariadb",
+        f"-u{user}",
+        f"-p{password}",
+        database,
+        "-e",
+        sql,
+    ]
+
+    if vertical:
+        cmd.insert(-2, "-E")  # Vertical output format
+
+    result = subprocess.run(
+        cmd,
+        capture_output=True,
+        text=True,
+        cwd=compose_dir,
+    )
+
+    return result.returncode, result.stdout, result.stderr
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser(
+        description="Execute SQL queries against the Nextcloud MariaDB database",
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+        epilog="""
+Examples:
+    %(prog)s "SELECT COUNT(*) FROM oc_notes"
+    %(prog)s "SELECT id, name FROM oc_oidc_clients"
+    %(prog)s -E "SELECT * FROM oc_users LIMIT 1"
+    %(prog)s --user nextcloud --password nextcloud "SHOW TABLES"
+        """,
+    )
+    parser.add_argument("sql", help="SQL statement to execute")
+    parser.add_argument(
+        "-u", "--user", default="root", help="Database user (default: root)"
+    )
+    parser.add_argument(
+        "-p",
+        "--password",
+        default="password",
+        help="Database password (default: password)",
+    )
+    parser.add_argument(
+        "-d",
+        "--database",
+        default="nextcloud",
+        help="Database name (default: nextcloud)",
+    )
+    parser.add_argument(
+        "-E",
+        "--vertical",
+        action="store_true",
+        help="Print output vertically (one column per line)",
+    )
+    parser.add_argument(
+        "--json",
+        action="store_true",
+        dest="json_output",
+        help="Request JSON output (if supported)",
+    )
+
+    args = parser.parse_args()
+
+    returncode, stdout, stderr = run_query(
+        sql=args.sql,
+        user=args.user,
+        password=args.password,
+        database=args.database,
+        vertical=args.vertical,
+        json_output=args.json_output,
+    )
+
+    if stdout:
+        print(stdout, end="")
+    if stderr:
+        # Filter out the password warning
+        filtered_stderr = "\n".join(
+            line
+            for line in stderr.splitlines()
+            if "Using a password on the command line interface can be insecure"
+            not in line
+        )
+        if filtered_stderr:
+            print(filtered_stderr, file=sys.stderr)
+
+    return returncode
+
+
+if __name__ == "__main__":
+    sys.exit(main())