feat: implement rollback command for deployments

- Added a new `rollback` command to roll back deployments to their previous release.
- Introduced `findRollbackCandidates` and `rollbackDeployment` functions to handle rollback logic.
- Updated CLI command definitions to include the new `rollback` command with an alias.
- Enhanced deployment conversion to use resolved images for buildable services.
- Introduced a new `graph` module to visualize Kubernetes resources and their relationships.
- Added tests for the new rollback functionality and graph rendering.
- Updated package version to 1.3.0.

types.d.ts

@@ -14,6 +14,8 @@ export interface KuberHookContext {
 export interface KuberBuildResult {
   built: string[];
   changed: string[];
+  /** Resolved immutable image references (`name -> registry/.../image:latest@sha256:...`) for buildable services. */
+  images: Record<string, string>;
 }
 
 export interface KuberResource {