pgAdmin 4: SQL injection in named restore point endpoint

SQL injection in pgAdmin 4's named restore point endpoint (POST /browser/server/restore_point/{gid}/{sid}). The user-supplied 'value' field was interpolated directly into the SQL string with str.format() instead of being passed as a bound parameter, allowing an authenticated pgAdmin user with a connected PostgreSQL session to inject additional statements through that endpoint. The injected SQL executes under the database role the user is already authenticated as. The defect does not cross a privilege boundary -- the user already has direct SQL access to that role through the Query Tool -- so the attacker gains no capability beyond what their database role already grants them. The marginal impact accounts for the fact that the injection path is not the documented SQL-execution interface, so a deployment that gates the Query Tool at the application layer could see SQL executed through a path it did not anticipate. Fix passes the restore point name as a bound parameter and schema-qualifies the function call as pg_catalog.pg_create_restore_point so a non-default search_path on the connection cannot redirect the call to a shadow definition. A regression test asserts the value arrives as a bound parameter and not spliced into the SQL string. This issue affects pgAdmin 4: from 1.0 before 9.16.