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.
Add new admin API endpoints for dashboard metrics and system-wide
realtime statistics:
- Add /admin/dashboard/summary endpoint with aggregated metrics
including requests, tokens, latency, masters, keys, and provider
keys statistics with time period filtering
- Add /admin/realtime endpoint for system-level realtime stats
aggregated across all masters
- Add status filter parameter to ListAPIKeys endpoint
- Add hour grouping option to log stats aggregation
- Update OpenAPI documentation with new endpoints and schemas
Introduce StatsService integration to admin and master handlers,
exposing realtime metrics (requests, tokens, QPS, rate limit status)
via new endpoints:
- GET /admin/masters/:id/realtime
- GET /v1/realtime
Also embed realtime stats in the existing GET /admin/masters/:id
response and change GlobalQPS default to 0 with validation to
reject negative values.
