feat(buildx): add automatic Buildx cleanup for stale builders and end-of-run cache pruning

ts/interfaces/index.ts

@@ -8,6 +8,11 @@ export interface ITsDockerConfig {
   platforms?: string[];  // ['linux/amd64', 'linux/arm64']
   push?: boolean;
   testDir?: string;
+  autoCleanup?: boolean;            // Automatically prune/remove tsdocker buildx resources
+  cleanupOnStart?: boolean;         // Run startup maintenance for stale tsdocker builders
+  buildxPruneUntil?: string;        // Prune cache older than this duration, e.g. '168h'; use '0' to disable
+  buildxPruneMaxUsedSpace?: string; // Keep each tsdocker builder cache below this size, e.g. '2gb'; use '0' to disable
+  removeCiBuilders?: boolean;       // Remove session-specific CI builders after each run
 }
 
 /**