refactor(config): stabilize synchronous experiment access and add real-time updates

- Revert getExperimentValue to a synchronous interface to maintain compatibility with existing callers.
- Add Config.updateExperimentalSettings() to support immediate application of /experiment set/unset changes.
- Implement CLI argument normalization to handle kebab-case, camelCase, and snake_case consistently.
- Enhance getExperimentFlagIdFromName to be more resilient to different naming conventions.
- Rename getNumericalRoutingEnabled to isNumericalRoutingEnabled for better idiomatic consistency.
- Update documentation in experimentation skill to recommend strongly-typed wrappers in Config.ts.
- Add regression tests for CLI overrides and update all relevant routing and command tests.
- Fix lint errors by removing unnecessary await/Promise.all for synchronous config methods.

packages/cli/src/ui/commands/experimentCommand.test.ts

@@ -18,6 +18,7 @@ describe('experimentCommand', () => {
       services: {
         config: {
           getExperimentValue: vi.fn(),
+          updateExperimentalSettings: vi.fn(),
         },
         settings: {
           merged: {