feat(web): W4-F rebuild agent conversation and drawer with agentui components

- Port agentui (MIT, ashish200729/agentui@b2b752b) Message/MessageBubble/MessageScroller,
  StreamingResponse, ToolResult/ToolApproval, TodoList, ApprovalCard, CodeBlock/FileDiff,
  Citations, PromptInput into components/agentui; drop motion/shiki/Next, switch colors,
  type scale, radii, durations and easing to semantic tokens, honour reduced motion
- Conversation: streaming cursor, collapsible thinking, tool cards with kind/scope/risk/
  idempotency badges and audit idempotency key, prominent server-rejection state for both
  whitelist rejections and unauthorized errors, compaction markers, budget meters with
  over-limit state, approval cards (admin session only), two-column final report
  (model said vs system verified with task/record links), follow-scroll with jump-to-bottom
- Composer: Enter send / Shift+Enter newline, stop = abort (confirmed), append,
  execute/plan_only switch, "execute this plan" from finished plan_only runs
- Session list sidebar with status filter and usage; reconnect/error banners with retry
- Drawer: route-derived context (entity/site/task), minimize to a live mini dock
- Fix stream refetch race when the run switches from loading to finished

Co-Authored-By: Claude Opus 5.5 <[email protected]>

apps/web/app/components/agentui/LICENSE-agentui.md

@@ -0,0 +1,32 @@
+# agentui 许可证
+
+本目录的组件改造自 [agentui](https://github.com/ashish200729/agentui)(<https://www.agentui.pro/>),
+取自提交 `b2b752bcadad032ce555f37dc7c8faabf395cefe`(2026-09-26)的 `components/agents/`。
+每个文件头注明了对应的上游文件与改造点:去掉 `motion` / `shiki` / Next.js 依赖,颜色、字号、圆角、
+时长、缓动换成本项目的语义 token(见 `docs/design/`),文案改中文,状态机按本项目的事件与对象裁剪。
+
+上游许可证原文如下。
+
+```
+MIT License
+
+Copyright (c) 2026 Saurabh Chauhan
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+```