Add admin endpoints to list and revoke child keys under a master.
Standardize OpenAPI responses to use ResponseEnvelope with MapData
for error payloads, and regenerate swagger specs accordingly.
Switch response envelope business code to numeric and make message
consistently present. Add trace_id and optional details, and remove the
duplicate DTO envelope definition. Improve middleware path exclusion
handling and add a time-based trace ID fallback if crypto RNG fails.
BREAKING CHANGE: response envelope `code` is now `int` (was `string`) and
`message` semantics/defaults changed; clients must update parsing.
Add response envelope middleware to standardize JSON responses as
`{code,data,message}` with consistent business codes across endpoints.
Update Swagger annotations and tests to reflect the new response shape.
BREAKING CHANGE: API responses are now wrapped in a response envelope; clients must read payloads from `data` and handle `code`/`message` fields.
