feat(classroom): 课堂助手模式UI优化、窗口智能识别与笔记生成加速

- 模式切换UI：采集路径改为卡片式选择器(图标+简述+动态说明面板)，采集模式添加功能描述，语言选项'混合'改为'多语'消除歧义

- 窗口识别优化：新增windowScorer关键词评分引擎(网课/会议+100,浏览器+50,系统窗口过滤)，3s轮询监听窗口变化，最小化容错(30s宽限期)

- 笔记生成加速：截图PNG改JPEG Q75压缩(体积-90%)，增量分析(每5帧后台静默分析)，课后纯文本合并(5s vs 原120s)，新增/merge-notes端点

- chore: 版本号 0.16.0 -> 0.16.1

Author: Aparencia

client/electron/ai/handlers/mergeNotesHandler.ts

@@ -0,0 +1,137 @@
+/**
+ * AI 片段笔记合并 Handler
+ *
+ * 处理 ai_merge_notes IPC 请求，将增量分析产生的多个片段笔记
+ * 合并为一份完整结构化笔记。纯文本操作，无需多模态模型。
+ * 对应端点：POST /api/v1/multimodal/merge-notes
+ */
+
+import { safeHandle } from '../../ipcUtils.js';
+import { logger } from '../../logger.js';
+import { callWithLocalFallback, gatewayUrl, type AIFeatureDef } from '../utils.js';
+import { generateText } from '../ollama/OllamaProvider.js';
+
+// ================================================================
+// IPC Handler
+// ================================================================
+
+/**
+ * ai_merge_notes — POST /api/v1/multimodal/merge-notes
+ */
+function register(): void {
+  safeHandle(
+    'ai_merge_notes',
+    async (
+      _event,
+      args: {
+        partials: string[];
+        duration?: number;   // 秒
+        language?: string;
+        authToken?: string;
+        userApiKey?: string;
+      },
+    ) => {
+      const startMs = Date.now();
+      const partialCount = args.partials?.length ?? 0;
+      logger.info(`[AI] [merge-notes] IPC received: partials=${partialCount}, duration=${args.duration ?? 0}s`);
+
+      if (!args.partials || args.partials.length === 0) {
+        throw new Error('partials 不能为空');
+      }
+
+      // 只有一个片段时直接返回
+      if (args.partials.length === 1) {
+        return {
+          content: args.partials[0].trim(),
+          modelUsed: 'none (single partial)',
+          source: 'local' as const,
+        };
+      }
+
+      const reqBody = {
+        partials: args.partials,
+        duration: args.duration ?? 0,
+        language: args.language ?? 'zh-CN',
+      };
+
+      logger.info(`[AI] [merge-notes] Target: ${gatewayUrl()}/api/v1/multimodal/merge-notes`);
+
+      interface MergeNotesResp {
+        content: string;
+        model_used: string;
+      }
+
+      try {
+        // 本地 Ollama 降级：纯文本合并
+        const localHandler = async (): Promise<MergeNotesResp> => {
+          const partsContent = args.partials
+            .map((p, i) => `### 片段 ${i + 1}\n\n${p.trim()}`)
+            .join('\n\n---\n\n');
+
+          const prompt = [
+            `以下是一门课程（总时长约 ${args.duration ?? 0} 秒）的 ${args.partials.length} 个片段笔记。`,
+            '请将它们合并为一份完整的结构化课堂笔记，要求：',
+            '1. 去除重复内容',
+            '2. 使用 Markdown 二级标题按知识模块组织',
+            '3. 补充片段间的衔接语句',
+            '4. 保留所有公式、定义、代码',
+            '5. 末尾添加「核心知识点摘要」',
+            '',
+            '---',
+            '',
+            partsContent,
+            '',
+            '---',
+            '',
+            '请直接输出合并后的 Markdown 笔记。',
+          ].join('\n');
+
+          const result = await generateText(
+            prompt,
+            '你是一个专业的课堂笔记整理助手，擅长将多个片段笔记合并为完整、连贯的结构化笔记。',
+            { temperature: 0.3, maxTokens: 4096 },
+          );
+
+          return {
+            content: result.content,
+            model_used: result.model,
+          };
+        };
+
+        const { data: resp, source, requestId } = await callWithLocalFallback<typeof reqBody, MergeNotesResp>(
+          '/api/v1/multimodal/merge-notes',
+          reqBody,
+          localHandler,
+          args.authToken,
+          args.userApiKey,
+          30000, // 纯文本合并，30s 超时足够
+        );
+
+        const elapsed = Date.now() - startMs;
+        logger.info(`[AI] [merge-notes] ✔ Success (${source}): content_length=${resp.content?.length ?? 0}, model=${resp.model_used}, total=${elapsed}ms, reqId=${requestId ?? 'N/A'}`);
+        return {
+          content: resp.content,
+          modelUsed: resp.model_used,
+          source,
+          requestId,
+        };
+      } catch (err) {
+        const elapsed = Date.now() - startMs;
+        const error = err instanceof Error ? err : new Error(String(err));
+        logger.error(`[AI] [merge-notes] ✖ Failed after ${elapsed}ms: ${error.message}`);
+        throw error;
+      }
+    },
+  );
+}
+
+// ================================================================
+// 功能定义导出
+// ================================================================
+
+export const feature: AIFeatureDef = {
+  id: 'ai_merge_notes',
+  name: 'AI 片段笔记合并',
+  version: '1.0.0',
+  register,
+};

client/electron/ai/index.ts

@@ -24,6 +24,7 @@ import { feature as rescueFeature } from './handlers/rescueHandler.js';
 import { feature as visionExtractFeature } from './handlers/visionExtractHandler.js';
 import { feature as sessionAnalyzeFeature } from './handlers/sessionAnalyzeHandler.js';
 import { feature as videoAnalyzeFeature } from './handlers/videoAnalyzeHandler.js';
+import { feature as mergeNotesFeature } from './handlers/mergeNotesHandler.js';
 
 // ================================================================
 // 功能注册表
@@ -45,6 +46,7 @@ const features: AIFeatureDef[] = [
   visionExtractFeature,
   sessionAnalyzeFeature,
   videoAnalyzeFeature,
+  mergeNotesFeature,
 ];
 
 // ================================================================

client/electron/ai/ollama/OllamaService.ts

@@ -287,6 +287,45 @@ export async function pullModel(
   _cachedStatus = null;
 }
 
+/**
+ * 删除本地模型
+ * @param modelName 模型名称（如 'qwen2.5:7b'）
+ */
+export async function deleteModel(modelName: string): Promise<void> {
+  const config = getOllamaConfig();
+  const baseUrl = config.baseUrl;
+
+  logger.info(`[Ollama] Deleting model: ${modelName}`);
+
+  const controller = new AbortController();
+  const timeoutId = setTimeout(() => controller.abort(), 30_000);
+
+  try {
+    const resp = await fetch(`${baseUrl}/api/delete`, {
+      method: 'DELETE',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ name: modelName }),
+      signal: controller.signal,
+    });
+    clearTimeout(timeoutId);
+
+    if (!resp.ok) {
+      const detail = await resp.text().catch(() => 'unknown error');
+      throw new Error(`Ollama delete failed: HTTP ${resp.status} - ${detail}`);
+    }
+
+    logger.info(`[Ollama] Model deleted successfully: ${modelName}`);
+    // 清除缓存，下次获取状态时刷新模型列表
+    _cachedStatus = null;
+  } catch (e) {
+    clearTimeout(timeoutId);
+    if (e instanceof Error && e.name === 'AbortError') {
+      throw new Error('Ollama delete timed out');
+    }
+    throw e;
+  }
+}
+
 /**
  * 应用启动时执行初始检测（如果 autoDetect 开启）
  */

client/electron/ai/ollama/index.ts

@@ -9,7 +9,7 @@
 
 import { ipcMain, BrowserWindow } from 'electron';
 import { logger } from '../../logger.js';
-import { getOllamaStatus, pullModel, initOllamaDetection } from './OllamaService.js';
+import { getOllamaStatus, pullModel, deleteModel, initOllamaDetection } from './OllamaService.js';
 import { loadOllamaConfig, updateOllamaConfig, getOllamaConfig } from './config.js';
 
 // ================================================================
@@ -85,6 +85,24 @@ export function registerOllamaHandlers(): void {
     }
   });
 
+  // ---- 删除模型 ----
+  ipcMain.handle('ollama:delete-model', async (_event, modelName: string) => {
+    if (!modelName || typeof modelName !== 'string') {
+      throw new Error('Invalid model name');
+    }
+
+    logger.info(`[Ollama] Delete model requested: ${modelName}`);
+
+    try {
+      await deleteModel(modelName);
+      return { success: true };
+    } catch (err) {
+      const errorMsg = err instanceof Error ? err.message : String(err);
+      logger.error(`[Ollama] Delete model failed: ${errorMsg}`);
+      throw err;
+    }
+  });
+
   logger.info('[Ollama] All IPC handlers registered');
 }
 
@@ -98,7 +116,7 @@ export async function initOllama(): Promise<void> {
 }
 
 // 统一导出
-export { getOllamaStatus, pullModel } from './OllamaService.js';
+export { getOllamaStatus, pullModel, deleteModel } from './OllamaService.js';
 export { getOllamaConfig, updateOllamaConfig, isLocalInferenceEnabled } from './config.js';
 export { generateText, generateVision, generateVisionMulti } from './OllamaProvider.js';
 export { isOllamaAvailable } from './OllamaService.js';

client/electron/captureHandlers.ts

@@ -13,6 +13,7 @@ import { VideoRecorder } from './videoRecorder.js';
 import type { VideoRecordOptions } from './videoRecorder.js';
 import { safeHandle, getMainWindowId } from './ipcUtils.js';
 import { logger } from './logger.js';
+import { scoreAndFilterWindows } from './windowScorer.js';
 
 // ================================================================
 // 模块级状态
@@ -34,6 +35,14 @@ const START_DEBOUNCE_MS = 500;
 /** 单调递增会话标识，用于防止 stop 后残留的 debounce 重启采集 */
 let captureSessionToken = 0;
 
+/** 窗口监听轮询定时器 */
+let windowWatchTimer: ReturnType<typeof setInterval> | null = null;
+
+/** 上一次窗口列表的 id 集合（用于 diff 检测变化） */
+let lastWindowIds: Set<string> = new Set();
+
+const WINDOW_WATCH_INTERVAL_MS = 3000;
+
 // ================================================================
 // 公共 API
 // ================================================================
@@ -120,21 +129,81 @@ export function registerCaptureHandlers(): void {
         thumbnailSize: { width: 240, height: 135 },
       });
 
-      return sources.map((src) => {
-        // 压缩缩略图，避免窗口多时 UI 内存占用过大
+      const rawWindows = sources.map((src) => {
         const thumb = src.thumbnail.isEmpty() ? src.thumbnail : src.thumbnail.resize({ width: 120 });
         return {
           id: src.id,
           title: src.name,
           thumbnail: thumb.toDataURL(),
         };
       });
+
+      // 智能评分、过滤与排序
+      return scoreAndFilterWindows(rawWindows);
     } catch (err) {
       logger.error('[IPC] screen_list_windows failed:', err);
       return [];
     }
   });
 
+  // ---- 窗口变化监听（轮询） ----
+
+  safeHandle('screen_watch_windows_start', async () => {
+    if (windowWatchTimer) return { success: true }; // 已在监听
+
+    logger.info('[IPC] 窗口监听已启动, interval=' + WINDOW_WATCH_INTERVAL_MS + 'ms');
+
+    windowWatchTimer = setInterval(async () => {
+      try {
+        const sources = await desktopCapturer.getSources({
+          types: ['window'],
+          thumbnailSize: { width: 240, height: 135 },
+        });
+
+        const currentIds = new Set(sources.map((s) => s.id));
+
+        // 检测是否有变化（新增或关闭窗口）
+        const hasChanged =
+          currentIds.size !== lastWindowIds.size ||
+          [...currentIds].some((id) => !lastWindowIds.has(id));
+
+        if (hasChanged) {
+          lastWindowIds = currentIds;
+
+          const rawWindows = sources.map((src) => {
+            const thumb = src.thumbnail.isEmpty() ? src.thumbnail : src.thumbnail.resize({ width: 120 });
+            return { id: src.id, title: src.name, thumbnail: thumb.toDataURL() };
+          });
+
+          const scored = scoreAndFilterWindows(rawWindows);
+
+          // 推送到渲染进程
+          const mainWindowId = getMainWindowId();
+          if (mainWindowId) {
+            const win = BrowserWindow.fromId(mainWindowId);
+            if (win && !win.isDestroyed()) {
+              win.webContents.send('screen_windows_changed', scored);
+            }
+          }
+        }
+      } catch (err) {
+        logger.error('[IPC] window watch poll error:', err);
+      }
+    }, WINDOW_WATCH_INTERVAL_MS);
+
+    return { success: true };
+  });
+
+  safeHandle('screen_watch_windows_stop', async () => {
+    if (windowWatchTimer) {
+      clearInterval(windowWatchTimer);
+      windowWatchTimer = null;
+      lastWindowIds = new Set();
+      logger.info('[IPC] 窗口监听已停止');
+    }
+    return { success: true };
+  });
+
   // ---- 系统音频捕获 ----
 
   safeHandle('audio_list_sources', async () => {

client/electron/ipc/channels.ts

@@ -25,6 +25,9 @@ export const IPC_CHANNELS = {
 
   // 采集相关
   SCREEN_LIST_WINDOWS: 'screen_list_windows',
+  SCREEN_WATCH_WINDOWS_START: 'screen_watch_windows_start',
+  SCREEN_WATCH_WINDOWS_STOP: 'screen_watch_windows_stop',
+  SCREEN_WINDOWS_CHANGED: 'screen_windows_changed',
   SCREEN_CAPTURE_START: 'screen_capture_start',
   SCREEN_CAPTURE_STOP: 'screen_capture_stop',
   SCREEN_CAPTURE_FRAME: 'screen_capture_frame',

client/electron/preload.ts

@@ -27,8 +27,11 @@ const ALLOWED_CHANNELS = [
   'ai_vision_extract',
   'ai_session_analyze',
   'ai_video_analyze',
+  'ai_merge_notes',
   'ai:set-gateway-url',
   'screen_list_windows',
+  'screen_watch_windows_start',
+  'screen_watch_windows_stop',
   'screen_capture_start',
   'screen_capture_stop',
   'audio_list_sources',
@@ -77,11 +80,13 @@ const ALLOWED_CHANNELS = [
   'ollama:get-status',
   'ollama:set-config',
   'ollama:pull-model',
+  'ollama:delete-model',
 ] as const;
 
 /** 允许渲染进程监听的事件 channel 白名单（主进程 → 渲染进程推送） */
 const ALLOWED_EVENT_CHANNELS = [
   'screen_capture_frame',
+  'screen_windows_changed',
   'audio_capture_chunk',
   'audio_capture_do_start',
   'audio_capture_do_stop',
@@ -213,6 +218,8 @@ contextBridge.exposeInMainWorld('electronAPI', {
       ipcRenderer.invoke('ollama:set-config', config),
     pullModel: (modelName: string) =>
       ipcRenderer.invoke('ollama:pull-model', modelName),
+    deleteModel: (modelName: string) =>
+      ipcRenderer.invoke('ollama:delete-model', modelName),
     onPullProgress: (callback: (...args: unknown[]) => void) => {
       const handler = (_event: unknown, ...args: unknown[]) => callback(...args);
       ipcRenderer.on('ollama:pull-progress', handler);