Add AI chat with skills management and model provider settings

- Model providers for OpenAI and Anthropic message formats (e.g. via
  Sub2API), with API keys encrypted at rest and never returned
- Skills tree with markdown editing, priorities, drafts, publishing and
  rollback; only published skills enter the chat prompt
- Chat page with tool calls over collected news and Binance USD-M
  klines, a persisted CONTEXT.md, reset, and stop-generation support
- Chat may only create skill drafts and update CONTEXT.md; publishing,
  deleting, moving and priority changes stay with the user

web/src/pages/chat/components/MessageList.vue

@@ -0,0 +1,85 @@
+<script lang="ts" setup>
+import { renderMarkdown } from "@/utils/markdown"
+
+export interface ToolCard {
+  id: string
+  name: string
+  arguments: Record<string, unknown>
+  /** 未返回时为 null */
+  result: string | null
+}
+
+export interface DisplayItem {
+  key: string
+  kind: "user" | "assistant"
+  text: string
+  toolCalls: ToolCard[]
+  stopped?: boolean
+  error?: string
+  /** 生成中：这次模型调用已结束，后续文字另起一条 */
+  closed?: boolean
+}
+
+defineProps<{ items: DisplayItem[] }>()
+
+const TOOL_LABELS: Record<string, string> = {
+  search_news: "检索新闻",
+  get_news: "读取新闻正文",
+  search_symbols: "查找交易对",
+  get_klines: "获取 K 线",
+  get_ticker: "获取 24h 行情",
+  list_skills: "列出 skills",
+  read_skill: "读取 skill",
+  propose_skill_edit: "提交 skill 草稿",
+  create_skill: "新建 skill（草稿）",
+  update_context: "更新 CONTEXT.md"
+}
+
+function prettyResult(result: string) {
+  try {
+    return JSON.stringify(JSON.parse(result), null, 2)
+  } catch {
+    // 前端拿到的是截断后的预览，可能不是完整 JSON
+    return result
+  }
+}
+</script>
+
+<template>
+  <div class="flex flex-col gap-4">
+    <div v-for="item in items" :key="item.key" :class="item.kind === 'user' ? 'self-end max-w-3/4' : 'self-stretch'">
+      <div v-if="item.kind === 'user'" class="whitespace-pre-wrap rounded-lg bg-[var(--el-color-primary-light-9)] px-3 py-2 text-sm">
+        {{ item.text }}
+      </div>
+      <div v-else class="flex flex-col gap-2">
+        <!-- markdown-it 已关闭 html，模型输出中的标签按文本显示 -->
+        <div v-if="item.text" class="markdown-body" v-html="renderMarkdown(item.text)" />
+        <el-collapse v-if="item.toolCalls.length" class="tool-cards">
+          <el-collapse-item v-for="call in item.toolCalls" :key="call.id" :name="call.id">
+            <template #title>
+              <div class="flex items-center gap-2 overflow-hidden text-xs">
+                <el-tag size="small" :type="call.result === null ? 'warning' : 'info'">
+                  {{ call.result === null ? "执行中" : "工具" }}
+                </el-tag>
+                <span class="font-bold">{{ TOOL_LABELS[call.name] ?? call.name }}</span>
+                <span class="truncate text-[var(--el-text-color-secondary)] font-mono">{{ JSON.stringify(call.arguments) }}</span>
+              </div>
+            </template>
+            <pre class="m-0 max-h-80 overflow-auto whitespace-pre-wrap break-all rounded bg-[var(--el-fill-color-light)] p-2 text-xs">{{ call.result === null ? "等待结果…" : prettyResult(call.result) }}</pre>
+          </el-collapse-item>
+        </el-collapse>
+        <div v-if="item.stopped" class="text-xs text-[var(--el-text-color-secondary)]">
+          （已停止生成）
+        </div>
+        <el-alert v-if="item.error" :title="item.error" type="error" :closable="false" show-icon />
+      </div>
+    </div>
+  </div>
+</template>
+
+<style scoped>
+.tool-cards :deep(.el-collapse-item__header) {
+  height: 32px;
+  line-height: 32px;
+}
+</style>