Make workspace, agent, and schedule automation consistent (#2186)

* feat(workspaces): align agent and schedule automation

Make workspace identity the shared placement boundary for MCP and CLI, while caller identity determines parentage. Keep heartbeats minimal and cron-based without changing legacy rolling interval semantics.

* test(cli): expect canonical schedule cadence

* fix(automation): preserve workspace and schedule compatibility

* fix(automation): preserve compatibility edges

* fix(workspaces): align MCP lifecycle resolution

* fix(workspaces): preserve creation intent

* fix(workspaces): preserve branch and schedule identity

packages/protocol/src/messages.workspaces.test.ts

@@ -1031,6 +1031,25 @@ describe("workspace message schemas", () => {
     expect(newWorktree.type).toBe("workspace.create.request");
     expect(newWorktree.source.kind).toBe("worktree");
 
+    const branchOff = WorkspaceCreateRequestSchema.parse({
+      type: "workspace.create.request",
+      requestId: "req-branch-off",
+      source: {
+        kind: "worktree",
+        cwd: "/tmp/repo",
+        action: "branch-off",
+        branchName: "feature/auth",
+        worktreeSlug: "feature-auth",
+      },
+    });
+    expect(branchOff.source).toEqual({
+      kind: "worktree",
+      cwd: "/tmp/repo",
+      action: "branch-off",
+      branchName: "feature/auth",
+      worktreeSlug: "feature-auth",
+    });
+
     // Directory source must also be accepted.
     const newDirectory = WorkspaceCreateRequestSchema.parse({
       type: "workspace.create.request",