Agent loop state machine refactor, unified LLM interface, and UI improvements

- Rewrite agent loop as Planning→Executing(N)→Completed state machine with
  per-step context isolation to prevent token explosion
- Split tools and prompts by phase (planning vs execution)
- Add advance_step/save_memo tools for step transitions and cross-step memory
- Unify LLM interface: remove duplicate types, single chat_with_tools path
- Add UTF-8 safe truncation (truncate_str) to prevent panics on Chinese text
- Extract CreateForm component, add auto-scroll to execution log
- Add report generation with app access URL, non-blocking title generation
- Add timer system, file serving, app proxy, exec module
- Update Dockerfile with uv, deployment config

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

web/src/components/CreateForm.vue

@@ -0,0 +1,142 @@
+<script setup lang="ts">
+import { ref, onMounted } from 'vue'
+
+const emit = defineEmits<{
+  submit: [requirement: string]
+  cancel: []
+}>()
+
+const requirement = ref('')
+const inputEl = ref<HTMLTextAreaElement>()
+
+const examples = [
+  { label: 'Todo 应用', text: '做一个 Todo List 应用：前端展示任务列表（支持添加、完成、删除），后端 FastAPI 提供增删改查 REST API，数据存 SQLite。完成后用 curl 跑一遍 E2E 测试验证所有接口正常。' },
+  { label: '贪吃蛇+排行榜', text: '做一个贪吃蛇游戏网站，前端用 HTML/JS，后端用 FastAPI 存储排行榜，支持提交分数和查看 Top10' },
+  { label: '抓取豆瓣 Top250', text: '用 Python 抓取豆瓣电影 Top250 并生成分析报告' },
+]
+
+onMounted(() => inputEl.value?.focus())
+
+function onSubmit() {
+  const text = requirement.value.trim()
+  if (text) emit('submit', text)
+}
+</script>
+
+<template>
+  <div class="create-form">
+    <h2>输入你的需求</h2>
+    <div class="create-examples">
+      <span
+        v-for="ex in examples"
+        :key="ex.label"
+        class="example-tag"
+        @click="requirement = ex.text"
+      >{{ ex.label }}</span>
+    </div>
+    <textarea
+      ref="inputEl"
+      v-model="requirement"
+      class="create-textarea"
+      placeholder="描述你想让 AI 做什么..."
+      rows="4"
+      @keydown.ctrl.enter="onSubmit"
+      @keydown.meta.enter="onSubmit"
+    />
+    <div class="create-hint">Ctrl+Enter 提交</div>
+    <div class="create-actions">
+      <button class="btn-cancel" @click="emit('cancel')">取消</button>
+      <button class="btn-confirm" @click="onSubmit" :disabled="!requirement.trim()">开始</button>
+    </div>
+  </div>
+</template>
+
+<style scoped>
+.create-form {
+  display: flex;
+  flex-direction: column;
+  gap: 12px;
+  width: 480px;
+}
+
+.create-form h2 {
+  font-size: 18px;
+  font-weight: 600;
+  color: var(--text-primary);
+}
+
+.create-examples {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 8px;
+}
+
+.example-tag {
+  padding: 4px 10px;
+  font-size: 12px;
+  background: var(--bg-tertiary);
+  color: var(--text-secondary);
+  border: 1px solid var(--border);
+  border-radius: 12px;
+  cursor: pointer;
+  transition: all 0.15s;
+}
+
+.example-tag:hover {
+  color: var(--accent);
+  border-color: var(--accent);
+  background: rgba(79, 195, 247, 0.08);
+}
+
+.create-textarea {
+  padding: 10px 12px;
+  background: var(--bg-secondary);
+  border: 1px solid var(--border);
+  border-radius: 6px;
+  color: var(--text-primary);
+  font-size: 14px;
+  font-family: inherit;
+  outline: none;
+  resize: vertical;
+  min-height: 80px;
+}
+
+.create-textarea:focus {
+  border-color: var(--accent);
+}
+
+.create-hint {
+  font-size: 12px;
+  color: var(--text-secondary);
+  text-align: right;
+}
+
+.create-actions {
+  display: flex;
+  gap: 8px;
+  justify-content: flex-end;
+}
+
+.btn-cancel {
+  padding: 8px 16px;
+  background: var(--bg-tertiary);
+  color: var(--text-secondary);
+  border: 1px solid var(--border);
+  border-radius: 6px;
+  font-size: 13px;
+}
+
+.btn-confirm {
+  padding: 8px 16px;
+  background: var(--accent);
+  color: var(--bg-primary);
+  border: none;
+  border-radius: 6px;
+  font-size: 13px;
+  font-weight: 500;
+}
+
+.btn-confirm:disabled {
+  opacity: 0.4;
+}
+</style>