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.

tests/lib/graph.test.ts

@@ -0,0 +1,175 @@
+import { describe, expect, test } from "bun:test";
+import type { KubernetesObject } from "@kubernetes/client-node";
+import {
+  buildNamespaceGraphs,
+  deriveNodeStatus,
+  renderNamespaceGraphs,
+} from "../../lib/graph";
+
+type TestObject = KubernetesObject & {
+  spec?: Record<string, unknown>;
+  status?: Record<string, unknown>;
+};
+
+const object = (
+  kind: string,
+  name: string,
+  extra: Partial<TestObject> = {},
+): TestObject => {
+  const { metadata, ...rest } = extra;
+  return {
+    apiVersion: "v1",
+    kind,
+    ...rest,
+    metadata: { name, namespace: "demo", ...metadata },
+  };
+};
+
+describe("ANSI resource graph", () => {
+  test("builds a deterministic owner tree and prefers owner edges", () => {
+    const deployment = object("Deployment", "web", {
+      status: { replicas: 1, readyReplicas: 1 },
+    });
+    const replicaSet = object("ReplicaSet", "web-123", {
+      metadata: {
+        ownerReferences: [
+          { apiVersion: "apps/v1", kind: "Deployment", name: "web", uid: "1" },
+        ],
+      },
+      status: { replicas: 1, readyReplicas: 1 },
+    });
+    const pod = object("Pod", "web-123-abc", {
+      metadata: {
+        labels: { app: "web" },
+        ownerReferences: [
+          {
+            apiVersion: "apps/v1",
+            kind: "ReplicaSet",
+            name: "web-123",
+            uid: "2",
+          },
+        ],
+      },
+      status: {
+        phase: "Running",
+        conditions: [{ type: "Ready", status: "True" }],
+      },
+    });
+    const service = object("Service", "web", {
+      spec: { selector: { app: "web" } },
+    });
+
+    const [graph] = buildNamespaceGraphs([
+      pod,
+      service,
+      replicaSet,
+      deployment,
+    ]);
+    expect(graph?.roots.map((node) => node.id)).toEqual([
+      "Deployment/web",
+      "Service/web",
+    ]);
+    expect(graph?.roots[0]?.children[0]?.id).toBe("ReplicaSet/web-123");
+    expect(graph?.roots[0]?.children[0]?.children[0]?.id).toBe(
+      "Pod/web-123-abc",
+    );
+    expect(graph?.roots[1]?.status).toEqual({ label: "1 ep", level: "good" });
+  });
+
+  test("hides stopped Deployment subtrees unless includeIdle is set", () => {
+    const deployment = object("Deployment", "stopped", {
+      status: { replicas: 0, readyReplicas: 0 },
+    });
+    const replicaSet = object("ReplicaSet", "stopped-old", {
+      metadata: {
+        ownerReferences: [
+          {
+            apiVersion: "apps/v1",
+            kind: "Deployment",
+            name: "stopped",
+            uid: "1",
+          },
+        ],
+      },
+      status: { replicas: 0, readyReplicas: 0 },
+    });
+    const pod = object("Pod", "stopped-old-pod", {
+      metadata: {
+        ownerReferences: [
+          {
+            apiVersion: "apps/v1",
+            kind: "ReplicaSet",
+            name: "stopped-old",
+            uid: "2",
+          },
+        ],
+      },
+      status: { phase: "Failed" },
+    });
+
+    expect(
+      buildNamespaceGraphs([deployment, replicaSet, pod])[0]?.roots,
+    ).toEqual([]);
+    const roots = buildNamespaceGraphs([deployment, replicaSet, pod], {
+      includeIdle: true,
+    })[0]?.roots;
+    expect(roots?.[0]?.id).toBe("Deployment/stopped");
+    expect(roots?.[0]?.children[0]?.children[0]?.id).toBe(
+      "Pod/stopped-old-pod",
+    );
+  });
+
+  test("derives good, warning, and bad statuses", () => {
+    expect(
+      deriveNodeStatus(
+        object("Pod", "ready", {
+          status: {
+            phase: "Running",
+            conditions: [{ type: "Ready", status: "True" }],
+          },
+        }),
+      ),
+    ).toEqual({ label: "ready", level: "good" });
+    expect(
+      deriveNodeStatus(
+        object("Deployment", "progressing", {
+          status: { replicas: 3, readyReplicas: 1 },
+        }),
+      ),
+    ).toEqual({ label: "1/3", level: "warn" });
+    expect(
+      deriveNodeStatus(
+        object("Pod", "failed", { status: { phase: "Failed" } }),
+      ),
+    ).toEqual({
+      label: "failed",
+      level: "bad",
+    });
+  });
+
+  test("renders tree connectors, kind colors, and ANSI status badges", () => {
+    const output = renderNamespaceGraphs([
+      {
+        namespace: "demo",
+        roots: [
+          {
+            id: "Deployment/web",
+            status: { label: "1/1", level: "good" },
+            children: [
+              {
+                id: "Pod/web-abc",
+                status: { label: "pending", level: "warn" },
+                children: [],
+              },
+            ],
+          },
+        ],
+      },
+    ]);
+
+    expect(output).toContain("demo\n└─ \u001b[34mDeployment/web\u001b[0m");
+    expect(output).toContain("\u001b[42m\u001b[30m 1/1 \u001b[0m");
+    expect(output).toContain("   └─ \u001b[32mPod/web-abc\u001b[0m");
+    expect(output).toContain("\u001b[43m\u001b[30m pending \u001b[0m");
+  });
+});