Replace per-request GetByKey calls with a singleflight-backed
RuntimeSettings snapshot loaded via ListSystemConfigsByKeys.
Invalidate snapshot on admin cap_* writes and via Redis pub/sub.
Simplify VerifyMiddleware and update PERFORMANCE.md status.
- Moved GORM/Redis CAPTCHA manager from internal/service/cap directly into the cohesive CAPTCHA app folder at internal/apps/cap/.
- Moved background system cleanup handler from internal/service/cleanup.go into internal/apps/upload/cleanup.go.
- Completely removed the global internal/service directory to keep module logic self-contained.
- Renamed the core utility engine pkg/diskcache to pkg/cache/disk to separate underlying utility code from db/config integrations.
- Renamed DiskCache struct in pkg/cache/disk to Cache to resolve revive package-name stuttering warning.
- Regenerated Swagger API documentation and confirmed all tests compile and pass with 0 linter issues.
- Relocated generic HTTP response helpers (Response, OK, Err, etc.) from internal/util/ to a dedicated internal/common/response/ package.
- Renamed ResponseAny to Any to resolve revive stuttering warnings.
- Moved session building options and cookie headers logic from internal/util/ to internal/apps/oauth/.
- Removed all direct imports of Gin/Sessions/HTTP frameworks from internal/util/ to keep general utilities 100% pure.
- Regenerated Swagger API documentation via make swagger.
- All tests and make code-check compile and pass with 0 issues.
ryan