refactor: remove legacy scheduling and analytics code

- Deleted the scheduler module and its associated functions, transitioning to OS-level scheduling.
- Removed the Analytics module and its related interfaces, retaining only a placeholder for backward compatibility.
- Updated ConfigValidator to warn about legacy schedule and analytics configurations.
- Cleaned up StartupValidator to remove diagnostics and schedule validation logic.
- Adjusted Load.ts to handle legacy flags for diagnostics and analytics.
- Removed unused diagnostics capturing functionality.

src/interface/ActivityHandler.ts

@@ -7,7 +7,7 @@ import type { Page } from 'playwright'
  * and perform all required steps on the provided page.
  */
 export interface ActivityHandler {
-  /** Optional identifier for diagnostics */
+  /** Optional identifier used in logging output */
   id?: string
   /**
    * Return true if this handler knows how to process the given activity.