Delete get() and waitForDependencies() facade functions from config/tui.ts.
Add TuiConfig.defaultLayer to AppLayer so the service is available via
AppRuntime.
Migrate all callers (attach.ts, thread.ts, plugin/runtime.ts) to
AppRuntime.runPromise(TuiConfig.Service.use(...)). Migrate tui.test.ts
(~28 calls) to the same pattern.
Rework test fixture: replace spyOn(TuiConfig, 'get') with mockTuiService
helper that mocks TuiConfig.Service.use at the Effect level. Update all
9 test files that spied on the old facades.
