fix: improve cross-device evidence, request diagnostics and prompt efficiency

apps/showcase_ui/src/app/components/llm-request-status/llm-request-status.component.html

@@ -0,0 +1,49 @@
+@if (sessionId()) {
+  <section class="model-requests" aria-label="模型请求状态">
+    @for (request of active(); track request.attempt_id) {
+      <div class="request-live" [class.retrying]="request.phase === 'retry_wait'" [class.stale]="unavailable()">
+        <div class="request-heading" aria-live="polite">
+          <span class="status-dot" [class.waiting]="!unavailable()"></span>
+          <strong>{{ unavailable() ? '请求状态暂时无法更新' : phase(request) }}</strong>
+          <span class="model">{{ request.model || '模型未记录' }} · {{ role(request) }}{{ request.is_fallback ? ' · 兜底模型' : '' }}</span>
+          <span class="elapsed">已用 {{ elapsed(request) }} 秒</span>
+        </div>
+        @if (!unavailable()) {
+          <p>{{ hint(request, now()) }} @if (request.phase !== 'retry_wait') { 本次请求最长等待 {{ request.timeout_seconds }} 秒。 }</p>
+        }
+        @if (request.error) { <p class="error">{{ request.error }}</p> }
+      </div>
+    }
+    @if (unavailable()) { <p class="notice" role="status">诊断信息暂时不可用；显示的是上次记录，不能据此判断任务是否卡住。</p> }
+    <details>
+      <summary>模型请求诊断 @if (requests().length) { <span>· 最近 {{ requests().length }} 次尝试</span> }</summary>
+      <div class="diagnostics-header"><span>时间按本机时区显示；下载文件同时包含 UTC 时间。</span><a [href]="downloadUrl()" download>下载完整诊断</a></div>
+      @if (loading()) { <p class="notice">正在加载请求记录…</p> }
+      @if (!loading() && !unavailable() && !requests().length) { <p class="notice">暂无请求诊断。旧任务没有记录的时间和用量无法补推。</p> }
+      <div class="request-history">
+        @for (request of requests(); track request.attempt_id) {
+          <details class="request-detail">
+            <summary><span>{{ request.started_at * 1000 | date:'HH:mm:ss' }}</span> {{ request.model || '模型' }} · {{ role(request) }} · {{ phase(request) }} @if (!request.active && !request.ended_at) { <span>（未记录结束，当前未在执行）</span> } @if (request.is_fallback) { <span class="fallback">兜底</span> }</summary>
+            <dl>
+              <dt>本地请求编号</dt><dd>{{ request.request_id }}</dd>
+              <dt>本次尝试编号</dt><dd>{{ request.attempt_id }}</dd>
+              <dt>服务端请求编号</dt><dd>{{ request.server_request_id || '服务未提供' }}</dd>
+              <dt>模型配置</dt><dd>{{ request.model || '未记录' }} / {{ request.reasoning_effort || '默认' }} · 第 {{ request.attempt }} 次请求，最多重试 {{ request.max_retries }} 次</dd>
+              <dt>输出 Token 上限</dt><dd>{{ request.max_output_tokens || '未设置（由模型服务决定）' }}</dd>
+              <dt>有效输出片段</dt><dd>{{ request.output_chunks ?? '未记录' }}（客户端计数，与服务端 SSE 事件数口径不同）</dd>
+              <dt>工具参数</dt><dd>{{ request.tool_argument_chars ?? '未记录' }} 字符 @for (tool of request.tools || []; track $index) { <span class="image-size">{{ tool.name || '工具名未提供' }} · {{ tool.argument_chars }} 字符</span> }</dd>
+              <dt>请求开始</dt><dd>{{ request.started_at * 1000 | date:'yyyy-MM-dd HH:mm:ss.SSS Z' }}</dd>
+              <dt>收到响应头</dt><dd>{{ request.headers_at ? (request.headers_at * 1000 | date:'HH:mm:ss.SSS') : '未记录' }} · HTTP {{ request.http_status || '未知' }}</dd>
+              <dt>首个有效输出</dt><dd>{{ request.first_output_at ? (request.first_output_at * 1000 | date:'HH:mm:ss.SSS') : '未收到／未记录' }}</dd>
+              <dt>最后有效输出</dt><dd>{{ request.last_output_at ? (request.last_output_at * 1000 | date:'HH:mm:ss.SSS') : '未收到／未记录' }}</dd>
+              <dt>结束时间</dt><dd>{{ request.ended_at ? (request.ended_at * 1000 | date:'HH:mm:ss.SSS') : '尚未记录' }}</dd>
+              <dt>输入图片</dt><dd>{{ request.images.length }} 张 @for (image of request.images; track $index) { <span class="image-size">{{ image.width && image.height ? image.width + ' × ' + image.height : '尺寸未知' }}</span> }</dd>
+              <dt>Token 用量</dt><dd>{{ request.usage ? '输入 ' + request.usage.prompt_tokens + ' / 输出 ' + request.usage.completion_tokens + ' / 合计 ' + request.usage.total_tokens : '未知（服务未报告）' }}</dd>
+              @if (request.error) { <dt>失败原因</dt><dd class="error">{{ request.error_type }} · {{ request.error }} · 阶段 {{ phase(request.failure_phase || '') }}</dd> }
+            </dl>
+          </details>
+        }
+      </div>
+    </details>
+  </section>
+}