[codex] Improve issue thread review flow (#4381)

## Thinking Path

> - Paperclip orchestrates AI agents for zero-human companies
> - Issue detail is where operators coordinate review, approvals, and
follow-up work with active runs
> - That thread UI needs to surface blockers, descendants, review
handoffs, and reply ergonomics clearly enough for humans to guide agent
work
> - Several small gaps in the issue-thread flow were making review and
navigation clunkier than necessary
> - This pull request improves the reply composer, descendant/blocker
presentation, interaction folding, and review-request handoff plumbing
together as one cohesive issue-thread workflow slice
> - The benefit is a cleaner operator review loop without changing the
broader task model

## What Changed

- restored and refined the floating reply composer behavior in the issue
thread
- folded expired confirmation interactions and improved post-submit
thread scrolling behavior
- surfaced descendant issue context and inline blocker/paused-assignee
notices on the issue detail view
- tightened large-board first paint behavior in `IssuesList`
- added loose review-request handoffs through the issue
execution-policy/update path and covered them with tests

## Verification

- `pnpm vitest run ui/src/pages/IssueDetail.test.tsx`
- `pnpm vitest run server/src/__tests__/issues-service.test.ts
server/src/__tests__/issue-execution-policy.test.ts`
- `pnpm exec vitest run --project @paperclipai/ui
ui/src/components/IssueChatThread.test.tsx
ui/src/components/IssueProperties.test.tsx
ui/src/components/IssuesList.test.tsx ui/src/lib/issue-tree.test.ts
ui/src/api/issues.test.ts`
- `pnpm exec vitest run --project @paperclipai/adapter-utils
packages/adapter-utils/src/server-utils.test.ts`
- `pnpm exec vitest run --project @paperclipai/server
server/src/__tests__/issue-comment-reopen-routes.test.ts -t "coerces
executor handoff patches into workflow-controlled review wakes|wakes the
return assignee with execution_changes_requested"`
- `pnpm exec vitest run --project @paperclipai/server
server/src/__tests__/issue-execution-policy.test.ts
server/src/__tests__/issues-service.test.ts`

## Visual Evidence

- UI layout changes are covered by the focused issue-thread component
and issue-detail tests listed above. Browser screenshots were not
attachable from this automated greploop environment, so reviewers should
use the running preview for final visual confirmation.

## Risks

- Moderate UI-flow risk: these changes touch the issue detail experience
in multiple spots, so regressions would most likely show up as
thread-layout quirks or incorrect review-handoff behavior

> For core feature work, check [`ROADMAP.md`](ROADMAP.md) first and
discuss it in `#dev` before opening the PR. Feature PRs that overlap
with planned core work may need to be redirected — check the roadmap
first. See `CONTRIBUTING.md`.

## Model Used

- OpenAI Codex GPT-5-based coding agent with tool use and code execution
in the Codex CLI environment

## 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 run tests locally and they pass
- [x] I have added or updated tests where applicable
- [x] If this change affects the UI, I have included before/after
screenshots or documented the visual verification path
- [ ] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [x] I will address all Greptile and reviewer comments before
requesting merge

---------

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

ui/src/components/IssueChatThread.test.tsx

@@ -14,6 +14,7 @@ import {
 } from "./IssueChatThread";
 import type {
   AskUserQuestionsInteraction,
+  RequestConfirmationInteraction,
   SuggestTasksInteraction,
 } from "../lib/issue-thread-interactions";
 
@@ -215,6 +216,39 @@ function createQuestionInteraction(
   };
 }
 
+function createExpiredRequestConfirmationInteraction(
+  overrides: Partial<RequestConfirmationInteraction> = {},
+): RequestConfirmationInteraction {
+  return {
+    id: "interaction-confirmation-expired",
+    companyId: "company-1",
+    issueId: "issue-1",
+    kind: "request_confirmation",
+    title: "Approve the plan",
+    status: "expired",
+    continuationPolicy: "wake_assignee_on_accept",
+    createdByAgentId: "agent-1",
+    createdByUserId: null,
+    resolvedByAgentId: null,
+    resolvedByUserId: "user-1",
+    createdAt: new Date("2026-04-06T12:04:00.000Z"),
+    updatedAt: new Date("2026-04-06T12:05:00.000Z"),
+    resolvedAt: new Date("2026-04-06T12:05:00.000Z"),
+    payload: {
+      version: 1,
+      prompt: "Approve the plan and let the assignee start implementation?",
+      acceptLabel: "Approve plan",
+      rejectLabel: "Request revisions",
+    },
+    result: {
+      version: 1,
+      outcome: "superseded_by_comment",
+      commentId: "comment-1",
+    },
+    ...overrides,
+  };
+}
+
 describe("IssueChatThread", () => {
   let container: HTMLDivElement;
 
@@ -535,6 +569,50 @@ describe("IssueChatThread", () => {
     });
   });
 
+  it("folds expired request confirmations into an activity row by default", async () => {
+    const root = createRoot(container);
+
+    await act(async () => {
+      root.render(
+        <MemoryRouter>
+          <IssueChatThread
+            comments={[]}
+            interactions={[createExpiredRequestConfirmationInteraction()]}
+            linkedRuns={[]}
+            timelineEvents={[]}
+            liveRuns={[]}
+            onAdd={async () => {}}
+            currentUserId="user-1"
+            userLabelMap={new Map([["user-1", "Dotta"]])}
+            showComposer={false}
+            enableLiveTranscriptPolling={false}
+          />
+        </MemoryRouter>,
+      );
+    });
+
+    expect(container.textContent).toContain("Dotta");
+    expect(container.textContent).toContain("updated this task");
+    expect(container.textContent).toContain("Expired confirmation");
+    expect(container.textContent).not.toContain("Approve the plan");
+
+    const toggleButton = Array.from(container.querySelectorAll("button")).find((button) =>
+      button.textContent?.includes("Expired confirmation"),
+    );
+    expect(toggleButton).toBeTruthy();
+
+    await act(async () => {
+      toggleButton?.dispatchEvent(new MouseEvent("click", { bubbles: true }));
+    });
+
+    expect(container.textContent).toContain("Approve the plan");
+    expect(container.textContent).toContain("Confirmation expired after comment");
+
+    act(() => {
+      root.unmount();
+    });
+  });
+
   it("renders the transcript directly from stable Paperclip messages", () => {
     const root = createRoot(container);
 
@@ -706,7 +784,7 @@ describe("IssueChatThread", () => {
     });
   });
 
-  it("keeps the composer inline with bottom breathing room and a capped editor height", () => {
+  it("keeps the composer floating with a capped editor height", () => {
     const root = createRoot(container);
 
     act(() => {
@@ -724,15 +802,85 @@ describe("IssueChatThread", () => {
       );
     });
 
+    const dock = container.querySelector('[data-testid="issue-chat-composer-dock"]') as HTMLDivElement | null;
+    expect(dock).not.toBeNull();
+    expect(dock?.className).toContain("sticky");
+    expect(dock?.className).toContain("bottom-[calc(env(safe-area-inset-bottom)+20px)]");
+    expect(dock?.className).toContain("z-20");
+
     const composer = container.querySelector('[data-testid="issue-chat-composer"]') as HTMLDivElement | null;
     expect(composer).not.toBeNull();
-    expect(composer?.className).not.toContain("sticky");
-    expect(composer?.className).not.toContain("bottom-0");
-    expect(composer?.className).toContain("pb-[calc(env(safe-area-inset-bottom)+1.5rem)]");
+    expect(composer?.className).toContain("rounded-md");
+    expect(composer?.className).not.toContain("rounded-lg");
+    expect(composer?.className).toContain("p-[15px]");
 
     const editor = container.querySelector('textarea[aria-label="Issue chat editor"]') as HTMLTextAreaElement | null;
     expect(editor?.dataset.contentClassName).toContain("max-h-[28dvh]");
     expect(editor?.dataset.contentClassName).toContain("overflow-y-auto");
+    expect(editor?.dataset.contentClassName).not.toContain("min-h-[72px]");
+
+    act(() => {
+      root.unmount();
+    });
+  });
+
+  it("renders the bottom spacer with zero height until the user has submitted", () => {
+    const root = createRoot(container);
+
+    act(() => {
+      root.render(
+        <MemoryRouter>
+          <IssueChatThread
+            comments={[{
+              id: "comment-spacer-1",
+              companyId: "company-1",
+              issueId: "issue-1",
+              authorAgentId: null,
+              authorUserId: "user-1",
+              body: "hello",
+              createdAt: new Date("2026-04-22T12:00:00.000Z"),
+              updatedAt: new Date("2026-04-22T12:00:00.000Z"),
+            }]}
+            linkedRuns={[]}
+            timelineEvents={[]}
+            liveRuns={[]}
+            onAdd={async () => {}}
+            enableLiveTranscriptPolling={false}
+          />
+        </MemoryRouter>,
+      );
+    });
+
+    const spacer = container.querySelector('[data-testid="issue-chat-bottom-spacer"]') as HTMLDivElement | null;
+    expect(spacer).not.toBeNull();
+    expect(spacer?.style.height).toBe("0px");
+
+    act(() => {
+      root.unmount();
+    });
+  });
+
+  it("omits the bottom spacer when the composer is hidden", () => {
+    const root = createRoot(container);
+
+    act(() => {
+      root.render(
+        <MemoryRouter>
+          <IssueChatThread
+            comments={[]}
+            linkedRuns={[]}
+            timelineEvents={[]}
+            liveRuns={[]}
+            onAdd={async () => {}}
+            showComposer={false}
+            enableLiveTranscriptPolling={false}
+          />
+        </MemoryRouter>,
+      );
+    });
+
+    const spacer = container.querySelector('[data-testid="issue-chat-bottom-spacer"]');
+    expect(spacer).toBeNull();
 
     act(() => {
       root.unmount();