- Refactor rate limiting mechanism to limit per API Key instead of per tenant (workspace).
- Update error code logic and Redis key naming conventions.
- Adjust quota usage statistics to display the QPS of the API Key closest to its limit.
- Add `API_KEY_RATE_LIMIT_EXCEEDED` error code.
- Refactor `QuotaExceededError` to support resource type localization.
- Optimize rate limiting service by implementing the sliding window algorithm.
- Add rate limit validation for tenant plans.
- Unify quota check decorator to support both synchronous and asynchronous operations.
- Enhance quota usage statistics endpoints.
- Add `default_free_plan.py` to define the configuration for the Community Free Plan.
- Refactor `quota_stub.py` as a unified entry point, delegating checks to `core/quota_manager`.
- Implement core logic in `quota_manager.py` to support retrieving quotas from the premium module or configuration files.
- Update `tenant_subscription_controller` to return Community Free Plan information.
