The goal of this refactoring is to eliminate the global configuration singleton (`config.Cfg`) and replace it with explicit dependency injection of a `Config` struct.
This commit includes the following partial changes:
- The `Config` struct in `internal/platform/config/config.go` has been updated with all necessary fields.
- Several platform packages (`db`, `cache`, `auth`, `http`, `jobs/sync`) have been modified to accept the `*config.Config` struct.
- The API server entry point (`cmd/api/main.go`) has been updated to load and provide the configuration.
- A new worker entry point (`cmd/worker/main.go`) has been created to house the background job runner, as per the architecture defined in `refactor.md`.
NOTE: The build is currently broken as this refactoring is incomplete. This commit is for saving progress as requested.
This commit refactors the API server startup logic in `cmd/api/main.go` to simplify the application's architecture.
Key changes:
- Consolidates the three separate HTTP servers (GraphQL API, GraphQL Playground, and Prometheus metrics) into a single `http.Server` instance.
- Uses a single `http.ServeMux` to route requests to the appropriate handlers on distinct paths (`/query`, `/playground`, `/metrics`).
- Removes the now-redundant `PlaygroundPort` from the application's configuration.
This change simplifies the server startup and shutdown logic, reduces resource usage, and makes the application's entry point cleaner and easier to maintain.
