refactor: streamline claude-mem integration and remove unused code

- Updated CODEMAP to reflect changes in fallback methods for package root discovery.
- Removed the `detectClaudePath` function and replaced its usage with direct references to `PACKAGE_NAME`.
- Eliminated the `claudePath` property from Settings interface and user settings configuration.
- Cleaned up path discovery logic by removing the npm list command method.
- Removed the `findExecutable` method from the Platform utility as it was no longer needed.

src/shared/types.ts

@@ -19,7 +19,6 @@ export interface Settings {
   backend?: string;
   embedded?: boolean;
   saveMemoriesOnClear?: boolean;
-  claudePath?: string;
   rollingCaptureEnabled?: boolean;
   rollingSummaryEnabled?: boolean;
   rollingSessionStartEnabled?: boolean;