fix(ui): leave agent detail after termination (#10451)

## Thinking Path

> - Paperclip is the open source app people use to manage AI agents for
work
> - The agent detail page lets operators inspect one agent and run
lifecycle actions from that context
> - Terminated agents are removed from the normal active-agent surface,
so the current detail route may no longer be fetchable after termination
> - Before this change, terminating an agent from its detail page
invalidated agent queries while leaving the browser on the now-stale
detail route
> - That refetch could surface an "Agent not found" error even though
the terminate action itself succeeded
> - The shared action button already owns the terminate mutation, so it
can notify detail-page callers when termination succeeds
> - This pull request redirects the detail page back to the agents list
after a successful terminate action
> - The benefit is that operators land on a valid route and the Back
button does not return them to the stale terminated-agent detail route

## Linked Issues or Issue Description

No direct public GitHub issue or PR was found for this detail-page
termination flow.

### What happened?

After terminating an agent from its detail page, the UI could remain on
that agent's detail route and show an "Agent not found" error after
query invalidation/refetch.

### Expected behavior

Once termination succeeds, the operator should leave the now-stale
detail page and land on a valid agents view.

### Steps to reproduce

1. Open a non-built-in agent detail page.
2. Use the overflow actions menu to terminate the agent.
3. Observe the post-termination route/error state.

### Paperclip version or commit

Current `master` before this PR.

### Deployment mode

Browser UI behavior, independent of a specific deployment mode.

Duplicate search: searched public GitHub issues and PRs for `agent not
found terminate`, `terminate agent detail`, and `Agent not found`; no
direct duplicate or viable in-flight PR was found.

## What Changed

- Added an optional `onTerminateSuccess` callback to
`AgentActionButtons`, fired only after the shared terminate mutation
succeeds.
- Wired `AgentDetail` to replace-navigate to `/agents/all` after
successful termination.
- Extended `AgentActionButtons` coverage for the terminate success path,
including API args, callback payload, and query invalidations.

## Verification

- `corepack pnpm exec vitest run
ui/src/components/AgentActionButtons.test.tsx`
- `corepack pnpm check:token-gates`
- `git diff --check origin/master..HEAD`
- Local diff scan for obvious tokens, credential filenames, and email
addresses found no matches.

## Risks

Low risk. The new callback is optional, only fires for successful
terminate actions, and preserves existing behavior for other
`AgentActionButtons` callers.

## Model Used

OpenAI Codex, GPT-5-based coding agent (`gpt-5`), tool use enabled for
repository inspection, editing, local verification, and GitHub CLI
operations. Context window details were not exposed by the runtime.

## Checklist

- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have searched GitHub for duplicate or related PRs and linked
them above
- [x] I have either (a) linked existing issues with `Fixes: #` / `Closes
#` / `Refs #` OR (b) described the issue in-PR following the relevant
issue template
- [x] I have not referenced internal/instance-local Paperclip issues or
links (only public GitHub `#NNN` / `github.com/paperclipai/paperclip`
URLs)
- [x] My branch name describes the change (e.g. `docs/...`, `fix/...`)
and contains no internal Paperclip ticket id or instance-derived details
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [x] All Paperclip CI gates are green
- [x] Greptile is 5/5 with no open P2s, recommendations, or follow-ups
- [x] I will address all Greptile and reviewer comments before
requesting merge

Co-authored-by: Paperclip <noreply@paperclip.ing>

ui/src/components/AgentActionButtons.test.tsx

@@ -1,6 +1,6 @@
 // @vitest-environment jsdom
 
-import type { ReactNode } from "react";
+import type { ComponentProps, ReactNode } from "react";
 import { flushSync } from "react-dom";
 import { createRoot } from "react-dom/client";
 import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
@@ -107,6 +107,7 @@ describe("AgentActionButtons", () => {
     mockAgentsApi.clearError.mockResolvedValue(makeAgent({ status: "idle" }));
     mockAgentsApi.pause.mockResolvedValue(makeAgent({ status: "paused" }));
     mockAgentsApi.resume.mockResolvedValue(makeAgent({ status: "idle" }));
+    mockAgentsApi.terminate.mockResolvedValue(makeAgent({ status: "terminated" }));
     mockAgentsApi.invoke.mockResolvedValue({ id: "run-1" });
     mockAgentsApi.resetSession.mockResolvedValue(undefined);
   });
@@ -124,11 +125,11 @@ describe("AgentActionButtons", () => {
     vi.clearAllMocks();
   });
 
-  function render(agent: Agent) {
+  function render(agent: Agent, props: Partial<ComponentProps<typeof AgentActionButtons>> = {}) {
     root = createRoot(container);
     root.render(
       <QueryClientProvider client={queryClient}>
-        <AgentActionButtons agent={agent} companyId="company-1" runLabel="Run Heartbeat" />
+        <AgentActionButtons agent={agent} companyId="company-1" runLabel="Run Heartbeat" {...props} />
       </QueryClientProvider>,
     );
   }
@@ -175,4 +176,33 @@ describe("AgentActionButtons", () => {
     expect(container.textContent).toContain("Pause");
     expect(container.textContent).not.toContain("Clear error");
   });
+
+  it("calls the terminate success handler after terminating an agent", async () => {
+    const onTerminateSuccess = vi.fn();
+    render(makeAgent(), { onTerminateSuccess });
+    await flushReact();
+
+    await act(async () => {
+      container.querySelector<HTMLButtonElement>('[aria-label="Open actions for Alpha Agent"]')?.click();
+    });
+    await flushReact();
+
+    const terminateButton = Array.from(document.body.querySelectorAll("button"))
+      .find((button) => button.textContent?.includes("Terminate"));
+    expect(terminateButton).toBeTruthy();
+
+    await act(async () => {
+      terminateButton?.click();
+    });
+    await flushReact();
+
+    expect(mockAgentsApi.terminate).toHaveBeenCalledWith("agent-1", "company-1");
+    expect(onTerminateSuccess).toHaveBeenCalledWith(expect.objectContaining({
+      id: "agent-1",
+      status: "terminated",
+    }));
+    expect(invalidateQueries).toHaveBeenCalledWith({ queryKey: ["agents", "detail", "agent-1"] });
+    expect(invalidateQueries).toHaveBeenCalledWith({ queryKey: ["agents", "detail", "alpha"] });
+    expect(invalidateQueries).toHaveBeenCalledWith({ queryKey: ["agents", "company-1"] });
+  });
 });

ui/src/components/AgentActionButtons.tsx

@@ -165,6 +165,7 @@ export function AgentActionButtons({
   workActionsDisabledReason,
   navigateToRunOnInvoke = true,
   onActionError,
+  onTerminateSuccess,
   pauseConfirm,
   hideTerminate = false,
   children,
@@ -193,6 +194,8 @@ export function AgentActionButtons({
    * omitted, failures surface as toasts (used by the list view).
    */
   onActionError?: (message: string | null) => void;
+  /** Called after termination succeeds so callers can leave now-hidden detail routes. */
+  onTerminateSuccess?: (agent: Agent) => void;
   /** Extra content rendered just before the overflow menu (e.g. live-run link). */
   children?: React.ReactNode;
   className?: string;
@@ -246,6 +249,9 @@ export function AgentActionButtons({
     onSuccess: (data, action) => {
       onActionError?.(null);
       invalidateAgent();
+      if (action === "terminate") {
+        onTerminateSuccess?.(data as Agent);
+      }
       if (action === "invoke" && navigateToRunOnInvoke && data && typeof data === "object" && "id" in data) {
         navigate(`/agents/${canonicalAgentRef}/runs/${(data as HeartbeatRun).id}`);
       }

ui/src/pages/AgentDetail.tsx

@@ -1157,6 +1157,7 @@ export function AgentDetail() {
             workActionsDisabled={hasInvalidOrgChain}
             workActionsDisabledReason="Repair this agent's reporting chain before assigning tasks or starting runs"
             onActionError={setActionError}
+            onTerminateSuccess={() => navigate("/agents/all", { replace: true })}
             hideTerminate={Boolean(builtInState)}
             pauseConfirm={
               builtInState