feat(desktop): Sidecar 健康度面板 + 重启后端能力

P1 已经把 backend-warning / backend-terminated 横幅做出来了；P2 把
lib.rs 那条 stdout/stderr/terminated 信息流真正落到一个常驻 UI 上：
- 右下角浮动状态点（绿/黄/红），轮询 /api/sys_health 决定颜色
- 点开抽屉看最近 200 行日志（ring buffer），含「重启后端」「复制日志」按钮

Rust：
- src-tauri/src/lib.rs：把 sidecar 启动抽出 spawn_backend_sidecar()，
  CommandChild 存进 SidecarHandle(Mutex<Option<CommandChild>>) 这个 state
- 新增 #[tauri::command] restart_backend_sidecar：kill 旧 child + 重新 spawn +
  emit 'backend-restarted' 给前端
- 监听任务 stdout/stderr emit 时不再用 format!("'{}'", ...) 包引号，原文直传；
  前端 hook 同时兼容旧形式（兜底剥引号）

前端：
- components/BackendHealth/useBackendEvents.ts：listen 四个事件 +
  ring buffer (MAX 200 行) + invoke restart + clipboard 复制日志
- BackendHealthIndicator.tsx：右下角浮动状态点，5s 轮询 /api/sys_health；
  连续 3 次失败或 backend-terminated 触发 → 红
- BackendLogPanel.tsx：右侧抽屉，深色 monospace 日志区 + 操作按钮
- 纯 web 环境（无 __TAURI_INTERNALS__）下静默不挂载

P3 / P4 还在路上。

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

BillNote_extension/src/background/main.ts

@@ -70,6 +70,7 @@ async function startTask(url: string): Promise<{ ok: boolean, taskId?: string, e
   // B 站：先在浏览器里抓字幕（带本地登录态 cookie），随提交带过去
   const prefetched = platform === 'bilibili' ? await fetchBilibiliSubtitle(url) : null
 
+  const formats = settings.formats || []
   try {
     const res = await fetch(`${backend}/api/generate_note`, {
       method: 'POST',
@@ -80,13 +81,15 @@ async function startTask(url: string): Promise<{ ok: boolean, taskId?: string, e
         quality: settings.quality,
         provider_id: settings.providerId,
         model_name: settings.modelName,
-        screenshot: settings.screenshot,
-        link: settings.link,
+        // backend 同时接受 format 数组与 screenshot/link 单独布尔；从 formats 派生保持单一真相源
+        format: [...formats],
+        screenshot: formats.includes('screenshot'),
+        link: formats.includes('link'),
         style: settings.style || undefined,
-        format: [
-          ...(settings.screenshot ? ['screenshot'] : []),
-          ...(settings.link ? ['link'] : []),
-        ],
+        extras: settings.extras || undefined,
+        video_understanding: settings.video_understanding || undefined,
+        video_interval: settings.video_understanding ? settings.video_interval : undefined,
+        grid_size: settings.video_understanding ? settings.grid_size : undefined,
         prefetched_transcript: prefetched ?? undefined,
       }),
     })

BillNote_extension/src/logic/constants.ts

@@ -7,9 +7,14 @@ export const DEFAULT_SETTINGS: Settings = {
   providerId: '',
   modelName: '',
   quality: 'medium',
+  formats: ['toc', 'summary'],
   screenshot: false,
   link: false,
-  style: '',
+  style: 'minimal',
+  extras: '',
+  video_understanding: false,
+  video_interval: 6,
+  grid_size: [2, 2],
 }
 
 export const MAX_TASKS = 30

BillNote_extension/src/logic/types.ts

@@ -40,6 +40,9 @@ export interface GenerateRequest {
   format?: string[]
   style?: string
   extras?: string
+  video_understanding?: boolean
+  video_interval?: number
+  grid_size?: [number, number]
   // 客户端在浏览器里直接抓到的字幕，跳过后端的 download_subtitles + 音频转写
   prefetched_transcript?: {
     language: string
@@ -78,14 +81,52 @@ export interface TaskRecord {
   result?: NoteResult
 }
 
+// 与 backend/app/gpt/prompt_builder.py note_styles 一一对齐
+export type NoteStyle =
+  | 'minimal' | 'detailed' | 'academic' | 'tutorial'
+  | 'xiaohongshu' | 'life_journal' | 'task_oriented'
+  | 'business' | 'meeting_minutes'
+
+// 与 backend/app/gpt/prompt_builder.py note_formats 一一对齐
+export type NoteFormat = 'toc' | 'link' | 'screenshot' | 'summary'
+
+export const NOTE_STYLES: Array<{ value: NoteStyle, label: string }> = [
+  { value: 'minimal', label: '精简' },
+  { value: 'detailed', label: '详细' },
+  { value: 'tutorial', label: '教程' },
+  { value: 'academic', label: '学术' },
+  { value: 'xiaohongshu', label: '小红书' },
+  { value: 'life_journal', label: '生活向' },
+  { value: 'task_oriented', label: '任务导向' },
+  { value: 'business', label: '商业风格' },
+  { value: 'meeting_minutes', label: '会议纪要' },
+]
+
+export const NOTE_FORMATS: Array<{ value: NoteFormat, label: string }> = [
+  { value: 'toc', label: '目录' },
+  { value: 'summary', label: 'AI 总结' },
+  { value: 'screenshot', label: '原片截图' },
+  { value: 'link', label: '原片跳转' },
+]
+
 export interface Settings {
   backendUrl: string
   providerId: string
   modelName: string
   quality: Quality
+  // 输出 format 的 toggle 集合（screenshot / link 与下方两个布尔保持联动）
+  formats: NoteFormat[]
   screenshot: boolean
   link: boolean
-  style: string
+  style: NoteStyle
+  extras: string
+  // 多模态视频理解：抽帧拼图喂给视觉模型，提升画面相关问题的回答质量
+  // 要求所选 model 是视觉模型（如 gpt-4o / gemini / claude-opus 系列），文字模型会忽略图片
+  video_understanding: boolean
+  // 抽帧间隔（秒），范围 1-30，默认 6
+  video_interval: number
+  // 拼图网格 [rows, cols]，每张拼图最多 rows*cols 帧。默认 [2,2]
+  grid_size: [number, number]
 }
 
 export interface ProviderUpdatePayload {

BillNote_extension/src/options/pages/General.vue

@@ -3,9 +3,16 @@ import { onMounted, ref } from 'vue'
 import { getProviders, ping } from '~/logic/api'
 import { settings, settingsReady } from '~/logic/storage'
 import { getModelsByProvider } from '~/logic/api'
-import type { Model, Provider } from '~/logic/types'
+import { NOTE_FORMATS, NOTE_STYLES, type Model, type NoteFormat, type Provider } from '~/logic/types'
 import { watch } from 'vue'
 
+function toggleFormat(value: NoteFormat, checked: boolean) {
+  const cur = settings.value.formats || []
+  settings.value.formats = checked
+    ? Array.from(new Set([...cur, value]))
+    : cur.filter(v => v !== value)
+}
+
 const providers = ref<Provider[]>([])
 const models = ref<Model[]>([])
 const status = ref<{ kind: 'idle' | 'ok' | 'err', text: string }>({ kind: 'idle', text: '' })
@@ -128,13 +135,67 @@ onMounted(async () => {
         </label>
         <label class="flex flex-col gap-1">
           <span class="text-gray-600">笔记风格</span>
-          <input v-model="settings.style" class="input" placeholder="留空使用默认">
+          <select v-model="settings.style" class="input">
+            <option v-for="s in NOTE_STYLES" :key="s.value" :value="s.value">{{ s.label }}</option>
+          </select>
         </label>
-        <label class="flex items-center gap-2">
-          <input v-model="settings.screenshot" type="checkbox"> 自动插入截图
+      </div>
+
+      <div class="flex flex-col gap-1 text-sm">
+        <span class="text-gray-600">输出形式（与 web 端 NoteForm 对齐）</span>
+        <div class="flex flex-wrap gap-x-4 gap-y-2">
+          <label v-for="f in NOTE_FORMATS" :key="f.value" class="flex items-center gap-2">
+            <input
+              type="checkbox"
+              :checked="(settings.formats || []).includes(f.value)"
+              @change="toggleFormat(f.value, ($event.target as HTMLInputElement).checked)"
+            >
+            {{ f.label }}
+          </label>
+        </div>
+      </div>
+
+      <label class="flex flex-col gap-1 text-sm">
+        <span class="text-gray-600">额外提示词（追加到 prompt 末尾）</span>
+        <textarea
+          v-model="settings.extras"
+          class="input resize-y"
+          rows="3"
+          placeholder="例如：重点关注游戏开发部分；保留所有专业术语原文"
+        />
+      </label>
+    </section>
+
+    <section class="section-card">
+      <h2 class="font-semibold">视频理解（多模态）</h2>
+      <p class="text-xs text-gray-500">
+        启用后会按抽帧间隔截取视频帧拼成网格图，连同字幕一起喂给视觉模型，提升画面相关问题的回答质量。
+        <strong class="text-amber-700">需要选择视觉模型</strong>（GPT-4o / Gemini / Claude 等），文字模型会忽略图片。
+      </p>
+      <label class="flex items-center gap-2 text-sm">
+        <input v-model="settings.video_understanding" type="checkbox">
+        启用视频理解
+      </label>
+      <div v-if="settings.video_understanding" class="grid grid-cols-3 gap-3 text-sm">
+        <label class="flex flex-col gap-1">
+          <span class="text-gray-600">抽帧间隔(秒, 1-30)</span>
+          <input v-model.number="settings.video_interval" type="number" min="1" max="30" class="input">
         </label>
-        <label class="flex items-center gap-2">
-          <input v-model="settings.link" type="checkbox"> 插入原片跳转链接
+        <label class="flex flex-col gap-1">
+          <span class="text-gray-600">拼图行 (1-10)</span>
+          <input
+            :value="settings.grid_size?.[0] ?? 2"
+            type="number" min="1" max="10" class="input"
+            @input="settings.grid_size = [Number(($event.target as HTMLInputElement).value) || 2, settings.grid_size?.[1] ?? 2]"
+          >
+        </label>
+        <label class="flex flex-col gap-1">
+          <span class="text-gray-600">拼图列 (1-10)</span>
+          <input
+            :value="settings.grid_size?.[1] ?? 2"
+            type="number" min="1" max="10" class="input"
+            @input="settings.grid_size = [settings.grid_size?.[0] ?? 2, Number(($event.target as HTMLInputElement).value) || 2]"
+          >
         </label>
       </div>
     </section>

BillNote_extension/src/popup/Popup.vue

@@ -4,7 +4,7 @@ import { detectPlatform } from '~/logic/platform'
 import { settings, settingsReady, tasks, tasksReady, upsertTask } from '~/logic/storage'
 import { generateNote, getTaskStatus, resolveImageUrl } from '~/logic/api'
 import { fetchBilibiliSubtitle } from '~/logic/bilibili-subtitle'
-import type { TaskRecord } from '~/logic/types'
+import { NOTE_FORMATS, NOTE_STYLES, type NoteFormat, type TaskRecord } from '~/logic/types'
 
 const tabUrl = ref<string>('')
 const tabTitle = ref<string>('')
@@ -67,19 +67,22 @@ async function start() {
   try {
     // B 站：在用户浏览器里直接抓字幕（带本地登录态 cookie），跳过后端的 download_subtitles 与音频转写
     const prefetched = platform.value === 'bilibili' ? await fetchBilibiliSubtitle(tabUrl.value) : null
+    const formats = settings.value.formats || []
     const { task_id } = await generateNote({
       video_url: tabUrl.value,
       platform: platform.value!,
       quality: settings.value.quality,
       provider_id: settings.value.providerId,
       model_name: settings.value.modelName,
-      screenshot: settings.value.screenshot,
-      link: settings.value.link,
+      // backend VideoRequest 同时接受 format 数组与 screenshot/link 单独布尔，从 formats 派生保持单一真相源
+      format: [...formats],
+      screenshot: formats.includes('screenshot'),
+      link: formats.includes('link'),
       style: settings.value.style || undefined,
-      format: [
-        ...(settings.value.screenshot ? ['screenshot'] : []),
-        ...(settings.value.link ? ['link'] : []),
-      ],
+      extras: settings.value.extras || undefined,
+      video_understanding: settings.value.video_understanding || undefined,
+      video_interval: settings.value.video_understanding ? settings.value.video_interval : undefined,
+      grid_size: settings.value.video_understanding ? settings.value.grid_size : undefined,
       prefetched_transcript: prefetched ?? undefined,
     })
     activeTaskId.value = task_id
@@ -108,6 +111,13 @@ function openOptions() {
   browser.runtime.openOptionsPage()
 }
 
+function toggleFormat(value: NoteFormat, checked: boolean) {
+  const cur = settings.value.formats || []
+  settings.value.formats = checked
+    ? Array.from(new Set([...cur, value]))
+    : cur.filter(v => v !== value)
+}
+
 async function openSidePanel() {
   // 只能在用户操作触发的同步上下文里调，且需要明确的 tabId
   try {
@@ -176,7 +186,7 @@ onUnmounted(() => {
     </div>
 
     <fieldset class="border rounded p-2 flex flex-col gap-2" :disabled="!supported || submitting">
-      <div class="grid grid-cols-3 gap-2 text-xs">
+      <div class="grid grid-cols-2 gap-2 text-xs">
         <label class="flex flex-col gap-1">
           <span class="text-gray-600">画质</span>
           <select v-model="settings.quality" class="border rounded px-1 py-0.5">
@@ -185,14 +195,76 @@ onUnmounted(() => {
             <option value="slow">高质</option>
           </select>
         </label>
-        <label class="flex items-center gap-1 mt-4">
-          <input v-model="settings.screenshot" type="checkbox"> 截图
-        </label>
-        <label class="flex items-center gap-1 mt-4">
-          <input v-model="settings.link" type="checkbox"> 跳转
+        <label class="flex flex-col gap-1">
+          <span class="text-gray-600">笔记风格</span>
+          <select v-model="settings.style" class="border rounded px-1 py-0.5">
+            <option v-for="s in NOTE_STYLES" :key="s.value" :value="s.value">{{ s.label }}</option>
+          </select>
         </label>
       </div>
 
+      <div class="flex flex-col gap-1 text-xs">
+        <span class="text-gray-600">输出形式</span>
+        <div class="flex flex-wrap gap-x-3 gap-y-1">
+          <label v-for="f in NOTE_FORMATS" :key="f.value" class="flex items-center gap-1">
+            <input
+              type="checkbox"
+              :checked="(settings.formats || []).includes(f.value)"
+              @change="toggleFormat(f.value, ($event.target as HTMLInputElement).checked)"
+            >
+            {{ f.label }}
+          </label>
+        </div>
+      </div>
+
+      <details class="text-xs">
+        <summary class="cursor-pointer text-gray-500">高级</summary>
+        <label class="flex flex-col gap-1 mt-2">
+          <span class="text-gray-600">额外提示词（追加到 prompt 末尾）</span>
+          <textarea
+            v-model="settings.extras"
+            class="border rounded px-1 py-1 resize-y"
+            rows="2"
+            placeholder="例如：重点关注游戏开发部分；保留所有专业术语原文"
+          />
+        </label>
+        <label class="flex items-center gap-2 mt-2">
+          <input v-model="settings.video_understanding" type="checkbox">
+          <span class="text-gray-600">启用视频理解（抽帧拼图喂视觉模型）</span>
+        </label>
+        <div v-if="settings.video_understanding" class="grid grid-cols-3 gap-2 mt-2">
+          <label class="flex flex-col gap-1">
+            <span class="text-gray-600">抽帧间隔(秒)</span>
+            <input
+              v-model.number="settings.video_interval"
+              type="number" min="1" max="30"
+              class="border rounded px-1 py-0.5"
+            >
+          </label>
+          <label class="flex flex-col gap-1">
+            <span class="text-gray-600">拼图行</span>
+            <input
+              :value="settings.grid_size?.[0] ?? 2"
+              type="number" min="1" max="10"
+              class="border rounded px-1 py-0.5"
+              @input="settings.grid_size = [Number(($event.target as HTMLInputElement).value) || 2, settings.grid_size?.[1] ?? 2]"
+            >
+          </label>
+          <label class="flex flex-col gap-1">
+            <span class="text-gray-600">拼图列</span>
+            <input
+              :value="settings.grid_size?.[1] ?? 2"
+              type="number" min="1" max="10"
+              class="border rounded px-1 py-0.5"
+              @input="settings.grid_size = [settings.grid_size?.[0] ?? 2, Number(($event.target as HTMLInputElement).value) || 2]"
+            >
+          </label>
+        </div>
+        <p v-if="settings.video_understanding" class="text-amber-700 mt-1">
+          ⚠ 需要选择视觉模型（GPT-4o / Gemini / Claude 等），文字模型会忽略图片
+        </p>
+      </details>
+
       <div class="text-xs text-gray-600">
         <span v-if="settings.providerId && settings.modelName">
           模型：{{ settings.modelName }}

BillNote_frontend/src-tauri/src/lib.rs

@@ -1,8 +1,14 @@
-use tauri::{Manager, Emitter};
+use tauri::{Manager, Emitter, State};
 use tauri_plugin_shell::ShellExt;
-use tauri_plugin_shell::process::CommandEvent;
+use tauri_plugin_shell::process::{CommandChild, CommandEvent};
 use std::env;
 use std::collections::HashMap;
+use std::path::Path;
+use std::sync::Mutex;
+use serde::Serialize;
+
+// Sidecar 子进程句柄，用 Mutex 包裹方便 restart 时杀旧进程
+struct SidecarHandle(Mutex<Option<CommandChild>>);
 
 #[cfg_attr(mobile, tauri::mobile_entry_point)]
 pub fn run() {
@@ -18,77 +24,31 @@ pub fn run() {
             }
 
             let exe_path = env::current_exe().expect("无法获取当前可执行文件路径");
-            let sidecar_dir = exe_path.parent().expect("无法获取可执行文件的父目录");
 
-            // 收集所有系统环境变量
-            let mut all_env_vars = HashMap::new();
-            for (key, value) in env::vars() {
-                all_env_vars.insert(key, value);
+            // 安装路径诊断：PyInstaller sidecar 在含非 ASCII / 空格的路径下经常炸（README 已警告但缺主动防御）
+            // 命中时把诊断信息 emit 给前端，由顶端横幅展示，不阻断启动
+            let diag = analyze_install_path(&exe_path);
+            if diag.path_has_non_ascii || diag.path_has_space || !diag.parent_writable {
+                let app_handle = app.handle().clone();
+                // 等前端首屏挂载好 listener；setup 阶段 window 已存在但 React 还没 render
+                // 用独立线程 + 标准 sleep，不引入 tokio 依赖
+                std::thread::spawn(move || {
+                    std::thread::sleep(std::time::Duration::from_millis(1500));
+                    if let Some(window) = app_handle.get_webview_window("main") {
+                        let _ = window.emit("backend-warning", &diag);
+                    }
+                });
             }
 
-            // 增强 PATH 环境变量，添加常见的二进制路径
-            let current_path = all_env_vars.get("PATH").cloned().unwrap_or_default();
-            let additional_paths = get_additional_binary_paths();
-            let enhanced_path = enhance_path_variable(&current_path, &additional_paths);
-            all_env_vars.insert("PATH".to_string(), enhanced_path);
-
-            // 打印一些关键环境变量用于调试
-            println!("Enhanced PATH: {}", all_env_vars.get("PATH").unwrap_or(&"Not found".to_string()));
-            println!("Total environment variables: {}", all_env_vars.len());
-
             // 检查 ffmpeg 是否在 PATH 中可用
             check_ffmpeg_availability();
 
-            // 启动 Python 后端侧车
-            let mut sidecar_command = app.shell().sidecar("BiliNoteBackend").unwrap();
-
-            // 设置所有环境变量到 sidecar
-            for (key, value) in &all_env_vars {
-                sidecar_command = sidecar_command.env(key, value);
-            }
-
-            let (mut rx, _child) = sidecar_command
-                .current_dir(sidecar_dir)
-                .spawn()
-                .expect("Failed to spawn sidecar");
-
-            // 获取主窗口句柄用于发送事件
-            let window = app.get_webview_window("main").unwrap();
-
-            tauri::async_runtime::spawn(async move {
-                // 读取诸如 stdout 之类的事件
-                while let Some(event) = rx.recv().await {
-                    match event {
-                        CommandEvent::Stdout(line) => {
-                            let output = String::from_utf8_lossy(&line);
-                            println!("Backend stdout: {}", output);
-
-                            // 发送到前端
-                            window
-                                .emit("backend-message", Some(format!("'{}'", output)))
-                                .expect("failed to emit event");
-                        }
-                        CommandEvent::Stderr(line) => {
-                            let error = String::from_utf8_lossy(&line);
-                            eprintln!("Backend stderr: {}", error);
-
-                            window
-                                .emit("backend-error", Some(format!("'{}'", error)))
-                                .expect("failed to emit event");
-                        }
-                        CommandEvent::Terminated(payload) => {
-                            println!("Backend terminated with code: {:?}", payload.code);
-                            window
-                                .emit("backend-terminated", Some(payload.code))
-                                .expect("failed to emit event");
-                            break;
-                        }
-                        _ => {
-                            println!("Backend event: {:?}", event);
-                        }
-                    }
-                }
-            });
+            // 启动 Sidecar 并把 child handle 存到 state，方便后续 restart_backend_sidecar 使用
+            let child = spawn_backend_sidecar(app.handle()).map_err(|e| {
+                eprintln!("Sidecar 启动失败: {}", e);
+                e
+            })?;
+            app.manage(SidecarHandle(Mutex::new(Some(child))));
 
             Ok(())
         })
@@ -96,7 +56,9 @@ pub fn run() {
             get_system_env_vars,
             find_executable_path,
             run_command_with_env,
-            test_ffmpeg_access
+            test_ffmpeg_access,
+            get_install_path_diagnostics,
+            restart_backend_sidecar
         ])
         .run(tauri::generate_context!())
         .expect("error while running tauri application");
@@ -268,6 +230,150 @@ async fn test_ffmpeg_access() -> Result<String, String> {
     run_command_with_env("ffmpeg".to_string(), vec!["-version".to_string()]).await
 }
 
+// 启动后端 Sidecar：负责装环境变量、spawn、挂 stdout/stderr/terminated 监听并 emit 给前端。
+// 第一次启动 + restart_backend_sidecar 都走这里，保持单一启动路径。
+fn spawn_backend_sidecar(app_handle: &tauri::AppHandle) -> Result<CommandChild, String> {
+    let exe_path = env::current_exe().map_err(|e| format!("无法获取可执行文件路径: {}", e))?;
+    let sidecar_dir = exe_path
+        .parent()
+        .ok_or("无法获取可执行文件父目录")?
+        .to_path_buf();
+
+    // 收集所有系统环境变量并增强 PATH（含 ffmpeg 常见安装位置）
+    let mut all_env_vars = HashMap::new();
+    for (key, value) in env::vars() {
+        all_env_vars.insert(key, value);
+    }
+    let current_path = all_env_vars.get("PATH").cloned().unwrap_or_default();
+    let additional_paths = get_additional_binary_paths();
+    let enhanced_path = enhance_path_variable(&current_path, &additional_paths);
+    all_env_vars.insert("PATH".to_string(), enhanced_path);
+
+    let mut sidecar_command = app_handle
+        .shell()
+        .sidecar("BiliNoteBackend")
+        .map_err(|e| format!("找不到 BiliNoteBackend sidecar: {}", e))?;
+    for (key, value) in &all_env_vars {
+        sidecar_command = sidecar_command.env(key, value);
+    }
+
+    let (mut rx, child) = sidecar_command
+        .current_dir(sidecar_dir)
+        .spawn()
+        .map_err(|e| format!("spawn sidecar 失败: {}", e))?;
+
+    // 异步监听 stdout / stderr / terminated 事件，转发到前端 webview
+    let app_handle_for_listener = app_handle.clone();
+    tauri::async_runtime::spawn(async move {
+        while let Some(event) = rx.recv().await {
+            // window 句柄每次重新取，允许窗口关闭重开
+            let window = app_handle_for_listener.get_webview_window("main");
+            match event {
+                CommandEvent::Stdout(line) => {
+                    let output = String::from_utf8_lossy(&line).to_string();
+                    println!("Backend stdout: {}", output);
+                    if let Some(w) = window {
+                        let _ = w.emit("backend-message", Some(output));
+                    }
+                }
+                CommandEvent::Stderr(line) => {
+                    let error = String::from_utf8_lossy(&line).to_string();
+                    eprintln!("Backend stderr: {}", error);
+                    if let Some(w) = window {
+                        let _ = w.emit("backend-error", Some(error));
+                    }
+                }
+                CommandEvent::Terminated(payload) => {
+                    println!("Backend terminated with code: {:?}", payload.code);
+                    if let Some(w) = window {
+                        let _ = w.emit("backend-terminated", Some(payload.code));
+                    }
+                    break;
+                }
+                _ => {
+                    println!("Backend event: {:?}", event);
+                }
+            }
+        }
+    });
+
+    Ok(child)
+}
+
+// 重启 sidecar：杀旧 child，spawn 新 child，回写到 state。
+#[tauri::command]
+fn restart_backend_sidecar(
+    state: State<'_, SidecarHandle>,
+    app: tauri::AppHandle,
+) -> Result<(), String> {
+    // 1. 拿出旧 child 并 kill（kill 失败也继续，可能进程已经退了）
+    {
+        let mut guard = state.0.lock().map_err(|e| format!("锁 sidecar state 失败: {}", e))?;
+        if let Some(child) = guard.take() {
+            let _ = child.kill();
+        }
+    }
+    // 2. 重新 spawn
+    let new_child = spawn_backend_sidecar(&app)?;
+    {
+        let mut guard = state.0.lock().map_err(|e| format!("锁 sidecar state 失败: {}", e))?;
+        *guard = Some(new_child);
+    }
+    // 3. emit 一个事件让前端知道已重启
+    if let Some(window) = app.get_webview_window("main") {
+        let _ = window.emit("backend-restarted", ());
+    }
+    Ok(())
+}
+
+// 安装路径诊断：PyInstaller 在含非 ASCII / 空格的路径下加载 _internal/* 经常炸；
+// 父目录不可写时模型 / 配置 / 日志也无法落盘
+#[derive(Serialize, Clone)]
+struct InstallPathDiagnostics {
+    exe_path: String,
+    path_has_non_ascii: bool,
+    path_has_space: bool,
+    parent_writable: bool,
+    platform: String,
+}
+
+fn analyze_install_path(exe_path: &Path) -> InstallPathDiagnostics {
+    let path_str = exe_path.to_string_lossy().to_string();
+    // 不在 ASCII 范围内的字符（中文 / 日文 / 西里尔等都会命中 PyInstaller 路径解析坑）
+    let has_non_ascii = path_str.chars().any(|c| !c.is_ascii());
+    // 空格本身在 Windows shell 引号场景偶尔出问题，且 macOS path 里也偶尔触发 sidecar 启动失败
+    let has_space = path_str.contains(' ');
+    // 父目录可写：PyInstaller 解压 _internal/、写日志、写配置都需要这个
+    let parent = exe_path.parent();
+    let parent_writable = parent
+        .and_then(|p| {
+            let probe = p.join(".bilinote_write_probe");
+            match std::fs::write(&probe, b"x") {
+                Ok(_) => {
+                    let _ = std::fs::remove_file(&probe);
+                    Some(true)
+                }
+                Err(_) => Some(false),
+            }
+        })
+        .unwrap_or(false);
+
+    InstallPathDiagnostics {
+        exe_path: path_str,
+        path_has_non_ascii: has_non_ascii,
+        path_has_space: has_space,
+        parent_writable,
+        platform: std::env::consts::OS.to_string(),
+    }
+}
+
+// Tauri 命令：让前端按需重新查询诊断结果（比如用户卸载到新目录后重启）
+#[tauri::command]
+fn get_install_path_diagnostics() -> InstallPathDiagnostics {
+    let exe_path = env::current_exe().unwrap_or_default();
+    analyze_install_path(&exe_path)
+}
+
 // 可选：添加一个函数来动态更新 sidecar 的环境变量
 #[tauri::command]
 async fn update_sidecar_environment(

BillNote_frontend/src/App.tsx

@@ -5,6 +5,8 @@ import { useTaskPolling } from '@/hooks/useTaskPolling.ts'
 import { useCheckBackend } from '@/hooks/useCheckBackend.ts'
 import { systemCheck } from '@/services/system.ts'
 import BackendInitDialog from '@/components/BackendInitDialog'
+import StartupBanner from '@/components/SystemDiagnostic/StartupBanner'
+import BackendHealthIndicator from '@/components/BackendHealth/BackendHealthIndicator'
 import Index from '@/pages/Index.tsx'
 import { HomePage } from './pages/HomePage/Home.tsx'
 
@@ -34,6 +36,7 @@ function App() {
   if (!initialized) {
     return (
       <>
+        <StartupBanner />
         <BackendInitDialog open={loading} />
       </>
     )
@@ -42,6 +45,8 @@ function App() {
   // 后端已初始化，渲染主应用
   return (
     <>
+      <StartupBanner />
+      <BackendHealthIndicator />
       <BrowserRouter>
         <Suspense fallback={<div className="flex h-screen items-center justify-center">加载中…</div>}>
           <Routes>

BillNote_frontend/src/components/BackendHealth/BackendHealthIndicator.tsx

@@ -0,0 +1,111 @@
+import { useEffect, useState } from 'react'
+import { useBackendEvents } from './useBackendEvents'
+import BackendLogPanel from './BackendLogPanel'
+
+// 健康度判定：
+// - 绿：sidecar running 且 /sys_health 通
+// - 黄：sidecar running 但 /sys_health 失败 (ffmpeg 缺等)
+// - 红：sidecar terminated 或 /sys_health 连续 3 次失败
+
+type Health = 'green' | 'yellow' | 'red' | 'unknown'
+
+const HEALTH_POLL_MS = 5000
+const SYS_HEALTH_PATH = '/api/sys_health'
+
+function backendBase(): string {
+  // 与 services/request.ts 用的一致
+  const fromEnv = (import.meta as any).env?.VITE_API_BASE_URL as string | undefined
+  return (fromEnv ?? '').replace(/\/$/, '')
+}
+
+const BackendHealthIndicator = () => {
+  const { status, isTauri, exitCode, logs, restart, copyLogs } = useBackendEvents()
+  const [open, setOpen] = useState(false)
+  const [healthCheckFailures, setHealthCheckFailures] = useState(0)
+  const [lastHealthOk, setLastHealthOk] = useState<boolean | null>(null)
+
+  // 仅在 Tauri 环境挂指示器；纯 web 用户由 useCheckBackend 接管
+  useEffect(() => {
+    if (!isTauri) return
+    let mounted = true
+
+    async function ping() {
+      try {
+        const res = await fetch(`${backendBase()}${SYS_HEALTH_PATH}`)
+        const ok = res.ok
+        if (!mounted) return
+        if (ok) {
+          setHealthCheckFailures(0)
+          setLastHealthOk(true)
+        }
+        else {
+          setHealthCheckFailures(c => c + 1)
+          setLastHealthOk(false)
+        }
+      }
+      catch {
+        if (!mounted) return
+        setHealthCheckFailures(c => c + 1)
+        setLastHealthOk(false)
+      }
+    }
+
+    ping()
+    const t = setInterval(ping, HEALTH_POLL_MS)
+    return () => {
+      mounted = false
+      clearInterval(t)
+    }
+  }, [isTauri])
+
+  if (!isTauri) return null
+
+  const health: Health = (() => {
+    if (status === 'terminated') return 'red'
+    if (healthCheckFailures >= 3) return 'red'
+    if (lastHealthOk === false) return 'yellow'
+    if (lastHealthOk === true) return 'green'
+    return 'unknown'
+  })()
+
+  const colorMap: Record<Health, string> = {
+    green: 'bg-green-500',
+    yellow: 'bg-amber-500',
+    red: 'bg-red-500',
+    unknown: 'bg-gray-400',
+  }
+
+  const labelMap: Record<Health, string> = {
+    green: '后端运行正常',
+    yellow: '后端运行中（部分检查未通过）',
+    red: status === 'terminated' ? `后端已退出 (code=${exitCode ?? 'unknown'})` : '后端无响应',
+    unknown: '后端状态未知',
+  }
+
+  return (
+    <>
+      <button
+        className="fixed right-3 bottom-3 z-[9998] flex items-center gap-2 rounded-full border bg-white px-3 py-1.5 text-xs shadow hover:shadow-md"
+        title={labelMap[health]}
+        onClick={() => setOpen(true)}
+      >
+        <span className={`inline-block h-2 w-2 rounded-full ${colorMap[health]}${health === 'red' || health === 'yellow' ? ' animate-pulse' : ''}`} />
+        <span className="text-gray-700">后端</span>
+      </button>
+
+      {open && (
+        <BackendLogPanel
+          status={status}
+          exitCode={exitCode}
+          logs={logs}
+          health={health}
+          onRestart={restart}
+          onCopyLogs={copyLogs}
+          onClose={() => setOpen(false)}
+        />
+      )}
+    </>
+  )
+}
+
+export default BackendHealthIndicator

BillNote_frontend/src/components/BackendHealth/BackendLogPanel.tsx

@@ -0,0 +1,108 @@
+import { useEffect, useRef, useState } from 'react'
+import type { LogEntry, BackendStatus } from './useBackendEvents'
+
+interface Props {
+  status: BackendStatus
+  exitCode: number | null
+  logs: LogEntry[]
+  health: 'green' | 'yellow' | 'red' | 'unknown'
+  onRestart: () => Promise<void>
+  onCopyLogs: () => Promise<boolean>
+  onClose: () => void
+}
+
+const BackendLogPanel = ({ status, exitCode, logs, health, onRestart, onCopyLogs, onClose }: Props) => {
+  const [restarting, setRestarting] = useState(false)
+  const [copied, setCopied] = useState(false)
+  const scrollRef = useRef<HTMLDivElement>(null)
+
+  // 新日志进来自动滚到底
+  useEffect(() => {
+    if (scrollRef.current)
+      scrollRef.current.scrollTop = scrollRef.current.scrollHeight
+  }, [logs])
+
+  async function handleRestart() {
+    setRestarting(true)
+    try { await onRestart() }
+    catch { /* errors already in log via useBackendEvents */ }
+    finally { setRestarting(false) }
+  }
+
+  async function handleCopy() {
+    const ok = await onCopyLogs()
+    setCopied(ok)
+    setTimeout(() => setCopied(false), 1500)
+  }
+
+  return (
+    <>
+      {/* 半透明遮罩 */}
+      <div className="fixed inset-0 z-[9998] bg-black/20" onClick={onClose} />
+
+      <aside className="fixed right-0 bottom-0 top-0 z-[9999] flex w-[480px] max-w-[90vw] flex-col border-l bg-white shadow-2xl">
+        <header className="flex items-center justify-between border-b px-4 py-3">
+          <div>
+            <h2 className="text-base font-semibold">后端运行状态</h2>
+            <div className="mt-0.5 text-xs text-gray-500">
+              {status === 'terminated'
+                ? `已退出（退出码 ${exitCode ?? 'unknown'}）`
+                : health === 'red'
+                  ? '运行中但无响应'
+                  : health === 'yellow'
+                    ? '运行中，部分系统检查未通过'
+                    : '运行正常'}
+            </div>
+          </div>
+          <button className="rounded p-1 text-gray-500 hover:bg-gray-100" onClick={onClose}>✕</button>
+        </header>
+
+        <div className="flex items-center gap-2 border-b px-4 py-2">
+          <button
+            className="rounded bg-blue-600 px-3 py-1 text-sm text-white hover:bg-blue-700 disabled:opacity-50"
+            disabled={restarting}
+            onClick={handleRestart}
+          >
+            {restarting ? '重启中…' : '重启后端'}
+          </button>
+          <button
+            className="rounded bg-gray-100 px-3 py-1 text-sm text-gray-700 hover:bg-gray-200"
+            onClick={handleCopy}
+          >
+            {copied ? '已复制 ✓' : '复制日志'}
+          </button>
+          <span className="ml-auto text-xs text-gray-400">
+            最近 {logs.length} 行
+          </span>
+        </div>
+
+        <div
+          ref={scrollRef}
+          className="flex-1 overflow-auto bg-gray-900 p-3 font-mono text-xs text-gray-100"
+        >
+          {logs.length === 0 ? (
+            <div className="text-gray-500 italic">暂无日志输出</div>
+          ) : (
+            logs.map((l, i) => (
+              <div
+                key={`${l.ts}-${i}`}
+                className={`whitespace-pre-wrap break-all leading-snug ${l.level === 'error' ? 'text-red-300' : 'text-gray-100'}`}
+              >
+                <span className="mr-2 text-gray-500">
+                  {new Date(l.ts).toISOString().slice(11, 19)}
+                </span>
+                {l.text}
+              </div>
+            ))
+          )}
+        </div>
+
+        <footer className="border-t px-4 py-2 text-xs text-gray-500">
+          后端进程退出 / 无响应时，先点「重启后端」；仍不行复制日志去 issue 反馈。
+        </footer>
+      </aside>
+    </>
+  )
+}
+
+export default BackendLogPanel

BillNote_frontend/src/components/BackendHealth/useBackendEvents.ts

@@ -0,0 +1,119 @@
+import { useEffect, useRef, useState } from 'react'
+
+// 桌面端 Sidecar 健康度。监听 Tauri 侧的 backend-message / backend-error /
+// backend-terminated / backend-restarted 事件，把 stdout/stderr 缓冲成 ring buffer，
+// 同时维护进程运行状态。
+
+const isTauri = typeof window !== 'undefined' && '__TAURI_INTERNALS__' in window
+
+export type LogLevel = 'info' | 'error'
+
+export interface LogEntry {
+  level: LogLevel
+  text: string
+  ts: number
+}
+
+export type BackendStatus = 'running' | 'terminated'
+
+const MAX_LOG_LINES = 200
+
+interface BackendEvents {
+  status: BackendStatus
+  exitCode: number | null
+  logs: LogEntry[]
+  /** 调 Tauri 命令重启 sidecar */
+  restart: () => Promise<void>
+  /** 复制全部日志到剪贴板 */
+  copyLogs: () => Promise<boolean>
+  isTauri: boolean
+}
+
+export function useBackendEvents(): BackendEvents {
+  const [status, setStatus] = useState<BackendStatus>('running')
+  const [exitCode, setExitCode] = useState<number | null>(null)
+  const [logs, setLogs] = useState<LogEntry[]>([])
+  // 用 ref 持有最新 logs 数组，append 时不被闭包陷阱卡到旧值
+  const logsRef = useRef<LogEntry[]>([])
+
+  function append(entry: LogEntry) {
+    const next = logsRef.current.concat(entry)
+    if (next.length > MAX_LOG_LINES)
+      next.splice(0, next.length - MAX_LOG_LINES)
+    logsRef.current = next
+    setLogs(next)
+  }
+
+  useEffect(() => {
+    if (!isTauri) return
+
+    let unlisteners: Array<() => void> = []
+
+    ;(async () => {
+      const { listen } = await import('@tauri-apps/api/event')
+
+      const offMsg = await listen<string>('backend-message', event => {
+        append({ level: 'info', text: stripQuotes(event.payload), ts: Date.now() })
+      })
+      const offErr = await listen<string>('backend-error', event => {
+        append({ level: 'error', text: stripQuotes(event.payload), ts: Date.now() })
+      })
+      const offTerm = await listen<number | null>('backend-terminated', event => {
+        setStatus('terminated')
+        setExitCode(event.payload ?? null)
+        append({
+          level: 'error',
+          text: `[Backend terminated] code=${event.payload ?? 'unknown'}`,
+          ts: Date.now(),
+        })
+      })
+      const offRestart = await listen('backend-restarted', () => {
+        setStatus('running')
+        setExitCode(null)
+        append({ level: 'info', text: '[Backend restarted]', ts: Date.now() })
+      })
+
+      unlisteners = [offMsg, offErr, offTerm, offRestart]
+    })()
+
+    return () => {
+      unlisteners.forEach(fn => fn())
+    }
+  }, [])
+
+  async function restart() {
+    if (!isTauri) return
+    const { invoke } = await import('@tauri-apps/api/core')
+    try {
+      await invoke('restart_backend_sidecar')
+    }
+    catch (e) {
+      append({ level: 'error', text: `[Restart failed] ${(e as Error).message ?? e}`, ts: Date.now() })
+      throw e
+    }
+  }
+
+  async function copyLogs() {
+    const text = logsRef.current
+      .map(l => `${new Date(l.ts).toISOString().slice(11, 19)} ${l.level === 'error' ? 'E' : 'I'} ${l.text}`)
+      .join('\n')
+    try {
+      await navigator.clipboard.writeText(text)
+      return true
+    }
+    catch {
+      return false
+    }
+  }
+
+  return { status, exitCode, logs, restart, copyLogs, isTauri }
+}
+
+// Rust 早期版本 emit 时把 stdout 包了一层 '...'，新版本已经直接 emit 原文。
+// 这里做兼容：去掉外层单引号（如果有的话）。
+function stripQuotes(s: string): string {
+  if (typeof s !== 'string') return String(s)
+  if (s.length >= 2 && s.startsWith("'") && s.endsWith("'"))
+    return s.slice(1, -1)
+  return s
+}

BillNote_frontend/src/components/SystemDiagnostic/StartupBanner.tsx

@@ -0,0 +1,123 @@
+import { useEffect, useState } from 'react'
+
+// 桌面端启动诊断横幅。监听 Tauri 侧 emit 的 backend-warning / backend-error / backend-terminated。
+// 只在 Tauri 环境生效；纯 web 环境（无 window.__TAURI_INTERNALS__）下静默不挂载。
+
+type Severity = 'info' | 'warning' | 'error'
+
+interface DiagnosticPayload {
+  exe_path?: string
+  path_has_non_ascii?: boolean
+  path_has_space?: boolean
+  parent_writable?: boolean
+  platform?: string
+}
+
+interface BannerState {
+  severity: Severity
+  title: string
+  detail: string
+  payload?: DiagnosticPayload
+  dismissible: boolean
+}
+
+const isTauri = typeof window !== 'undefined' && '__TAURI_INTERNALS__' in window
+
+function describeWarning(payload: DiagnosticPayload): { title: string; detail: string } {
+  const parts: string[] = []
+  if (payload.path_has_non_ascii) {
+    parts.push('安装路径包含非 ASCII 字符（中文 / 日文等）')
+  }
+  if (payload.path_has_space) {
+    parts.push('安装路径包含空格')
+  }
+  if (payload.parent_writable === false) {
+    parts.push('安装目录不可写（缺少权限或只读）')
+  }
+  return {
+    title: '检测到可能导致后端启动失败的安装路径',
+    detail:
+      `${parts.join('；')}。\n` +
+      '建议把 BiliNote 重新安装到一个纯英文、无空格、可写的路径下（如 C:\\BiliNote\\ 或 /Applications/）。\n' +
+      `当前路径：${payload.exe_path || '未知'}`,
+  }
+}
+
+const StartupBanner = () => {
+  const [banner, setBanner] = useState<BannerState | null>(null)
+
+  useEffect(() => {
+    if (!isTauri) return
+
+    let unlisteners: Array<() => void> = []
+
+    ;(async () => {
+      const { listen } = await import('@tauri-apps/api/event')
+
+      const offWarning = await listen<DiagnosticPayload>('backend-warning', event => {
+        const { title, detail } = describeWarning(event.payload || {})
+        setBanner({
+          severity: 'warning',
+          title,
+          detail,
+          payload: event.payload,
+          dismissible: true,
+        })
+      })
+
+      const offTerminated = await listen<number | null>('backend-terminated', event => {
+        setBanner({
+          severity: 'error',
+          title: '后端进程已退出',
+          detail: `退出码：${event.payload ?? '未知'}。打开「部署监控」或重启应用以恢复。`,
+          dismissible: false,
+        })
+      })
+
+      // backend-error 是 sidecar stderr，量大噪音多，这里不直接展示，留给 P2 的日志面板。
+      unlisteners = [offWarning, offTerminated]
+    })()
+
+    return () => {
+      unlisteners.forEach(fn => fn())
+    }
+  }, [])
+
+  if (!banner) return null
+
+  const colorByLevel: Record<Severity, string> = {
+    info: 'bg-blue-50 border-blue-300 text-blue-900',
+    warning: 'bg-amber-50 border-amber-300 text-amber-900',
+    error: 'bg-red-50 border-red-300 text-red-900',
+  }
+
+  const iconByLevel: Record<Severity, string> = {
+    info: 'ℹ️',
+    warning: '⚠️',
+    error: '✕',
+  }
+
+  return (
+    <div
+      className={`fixed left-0 right-0 top-0 z-[9999] flex items-start gap-3 border-b px-4 py-2 text-sm shadow-sm ${colorByLevel[banner.severity]}`}
+    >
+      <span className="text-lg">{iconByLevel[banner.severity]}</span>
+      <div className="flex-1 min-w-0">
+        <div className="font-medium">{banner.title}</div>
+        <pre className="mt-0.5 whitespace-pre-wrap break-words font-sans text-xs opacity-90">
+          {banner.detail}
+        </pre>
+      </div>
+      {banner.dismissible && (
+        <button
+          className="shrink-0 rounded px-2 py-0.5 text-xs hover:bg-black/10"
+          onClick={() => setBanner(null)}
+        >
+          知道了
+        </button>
+      )}
+    </div>
+  )
+}
+
+export default StartupBanner