---
phase: 06-
plan: 02
subsystem: ui
tags: [mention, dropdown, chip, keyboard]
requires:
  - phase: 06-
    provides: reference payload contract and soft-fail behavior
provides:
  - thread-scoped @ candidate aggregation
  - dropdown filtering and keyboard navigation
  - removable reference chips with max-limit enforcement
affects: [prompt-input, submit-payload, e2e]
tech-stack:
  added: []
  patterns:
    - current-thread-only reference candidates
    - IME-safe keyboard handling for mention selection
key-files:
  created:
    - .planning/phases/06-/06-02-SUMMARY.md
  modified:
    - frontend/src/components/workspace/input-box.tsx
    - frontend/src/components/ai-elements/prompt-input.tsx
    - frontend/src/core/uploads/hooks.ts
    - frontend/src/components/ui/dropdown-menu.tsx
key-decisions:
  - "@候选严格限定在当前 thread 的 artifacts + uploads。"
  - "引用上限固定为 10，超限 toast 并阻止新增。"
requirements-completed: [ATREF-01, ATREF-02]
duration: 25 min
completed: 2026-04-15
---

# Phase 06 Plan 02 Summary

**完成输入框 `@` 引用交互闭环：候选展示、过滤、选择、chip 渲染、删除、键盘操作与上限控制。**

## Verification

- `cd frontend && pnpm -s typecheck`
  - passed

## Outcome

- 输入 `@` 可拉起 `DropdownMenu` 候选并按 query 过滤。
- 选择候选后以 chip 展示，可删除且支持去重。
- `ArrowUp/ArrowDown/Enter/Escape/Backspace` 与 `isComposing` 保护已落地。