feat(agent): show pending response indicator

[AnthonyRonning]

Summary

• show the same three-dot assistant loader in Agent Mode while a sent user turn waits for its first visible assistant activity
• share the pending assistant turn UI with Unified Chat
• stop the loader on thinking, content, tool, permission, system, error, cancellation, or completion
• add focused timeline predicate coverage

Validation

• pre-commit hook: Prettier, TypeScript/Vite production build, 80 Bun tests
• ESLint: 0 errors (12 existing warnings)
• manual macOS desktop smoke test: dots appeared after send and disappeared when GLM thinking/content arrived
• independent review: no confirmed issues

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Summary by CodeRabbit

• New Features

  • Added a consistent “Maple is responding” indicator while waiting for the assistant’s first response.
  • The indicator now appears appropriately in both standard and agent chat views.
  • Added accessible status labeling for the response indicator.

• Bug Fixes

  • Prevented the loading indicator from appearing after assistant activity has started or when no user message is present.

[cloudflare-workers-and-pages]

Deploying maple with    Cloudflare Pages

Latest commit:	62ef561
Status:	✅  Deploy successful!
Preview URL:	https://b049e32a.maple-ca8.pages.dev
Branch Preview URL:	https://codex-maple-agent-pending-in.maple-ca8.pages.dev

View logs

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 7594553e-e560-4189-bf97-375a9c3c0349

📥 Commits

Reviewing files that changed from the base of the PR and between c3f1f9c and 62ef561.

📒 Files selected for processing (5)

• frontend/src/components/AgentMode.tsx
• frontend/src/components/UnifiedChat.tsx
• frontend/src/components/chat/ChatTurn.tsx
• frontend/src/services/agentTimeline.test.ts
• frontend/src/services/agentTimeline.ts

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📝 Walkthrough

Walkthrough

Adds a reusable pending assistant turn, centralizes loader visibility logic, and integrates the placeholder into unified and agent chat timelines with accessibility markup and helper tests.

Changes

Assistant pending loader

Layer / File(s)	Summary
Loader visibility contract frontend/src/services/agentTimeline.ts, frontend/src/services/agentTimeline.test.ts	Adds and tests shouldShowAgentAssistantLoader, which shows the loader only while a user turn is awaiting assistant activity.
Reusable pending assistant turn frontend/src/components/chat/ChatTurn.tsx, frontend/src/components/UnifiedChat.tsx	Introduces ChatAssistantPendingTurn with accessible status markup and uses it for the unified chat initial loader.
Agent timeline integration frontend/src/components/AgentMode.tsx	Passes response-pending state into AgentTimeline and renders the shared pending turn when the timeline helper allows it.

Estimated code review effort: 2 (Simple) | ~10 minutes

Sequence Diagram(s)

sequenceDiagram
  participant Chat as Chat UI
  participant Timeline as AgentTimeline
  participant Helper as shouldShowAgentAssistantLoader
  participant Pending as ChatAssistantPendingTurn
  Chat->>Timeline: Pass isResponsePending
  Timeline->>Helper: Evaluate turns and pending state
  Helper-->>Timeline: Return loader visibility
  Timeline->>Pending: Render pending assistant turn

Loading

Possibly related PRs

• OpenSecretCloud/Maple#614: Refactors assistant-turn rendering and waiting-for-first-assistant placeholder behavior used by this loader change.

Suggested reviewers: devin-ai-integration[bot], github-actions[bot]

Poem

I twitch my nose as responses start,
A pulsing reply warms every chart.
The timeline knows when to wait,
Then Maple speaks—no empty state.
Three dots dance, status bright.

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title is concise and accurately summarizes the main change: showing a pending response indicator in Agent Mode.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch codex-maple-agent-pending-indicator

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[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no bugs or issues to report.