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/services/path-discovery.ts

@@ -182,7 +182,7 @@ export class PathDiscovery {
     // Method 2: Walk up from current module location
     const currentFile = fileURLToPath(import.meta.url);
     let currentDir = dirname(currentFile);
-    
+
     for (let i = 0; i < 10; i++) {
       const packageJsonPath = join(currentDir, 'package.json');
       if (existsSync(packageJsonPath)) {
@@ -198,21 +198,6 @@ export class PathDiscovery {
       currentDir = parentDir;
     }
 
-    // Method 3: Try npm list command
-    try {
-      const npmOutput = execSync('npm list -g claude-mem --json 2>/dev/null || npm list claude-mem --json 2>/dev/null', {
-        encoding: 'utf8'
-      });
-      const npmData = JSON.parse(npmOutput);
-
-      if (npmData.dependencies?.['claude-mem']?.resolved) {
-        this._packageRoot = dirname(npmData.dependencies['claude-mem'].resolved);
-        return this._packageRoot;
-      }
-    } catch {
-      // Continue to error
-    }
-
     throw new Error('Cannot locate claude-mem package root. Ensure claude-mem is properly installed.');
   }