feat: 视觉能力去 Electron 化，经 HostBridge.screen 注入（迁移阶段1-A9）

- HostBridge 新增可选 screen 服务（listDisplays/primaryDisplay/dipToScreenPoint/
  displayMatching/captureDisplay），vision 3 处、cv-vision 2 处动态 import(electron)
  全部改为 requireScreenService()；未注入时抛稳定的 host_unavailable
- demo 宿主 src/main/index.ts 用 desktopCapturer/screen 实现 screen 服务
- check-deps.mjs 升级：新增动态 import()/require() 扫描（旧正则实测 0 命中的盲区），
  合成用例验证命中，升级后真实源码 0 违规
- 包依赖闭包：补声明 @cantoo/pdf-lib、@napi-rs/canvas、pdfjs-dist
- cv-vision 测试从 vi.mock(electron) 改为宿主桥注入，11/11 通过

packages/rpa-core/src/capabilities/vision.ts

@@ -3,6 +3,7 @@ import { promises as fs } from "node:fs";
 import { PNG } from "pngjs";
 import { register } from "../engine/registry";
 import { RuntimeError } from "../engine/types";
+import { requireScreenService, type HostDisplay } from "../engine/host-bridge";
 import { powershell, psString } from "../driver/windows/powershell";
 
 function text(args: Record<string, unknown>, keys: string[], fallback = ""): string {
@@ -15,28 +16,20 @@ function text(args: Record<string, unknown>, keys: string[], fallback = ""): str
  * 逐屏截图后按各自物理原点拼到一张画布上——目标在副屏也能搜到。
  * 返回 originX/originY = 拼接画布左上角对应的屏幕物理坐标（副屏在主屏左侧时为负），用于结果坐标平移。 */
 async function captureVirtualScreenPng(): Promise<{ png: PNG; originX: number; originY: number }> {
-  const { desktopCapturer, screen } = await import("electron");
-  const displays = screen.getAllDisplays();
+  const screenHost = requireScreenService();
+  const displays = screenHost.listDisplays();
   if (displays.length === 0) throw new RuntimeError("desktop_error", "无法获取屏幕信息");
-  // 每屏按自己的物理分辨率截图（display_id 匹配 → 缩略图尺寸匹配 → 按物理原点排序对位）
-  const captures: { display: Electron.Display; origin: { x: number; y: number }; png: PNG }[] = [];
+  // 每屏按自己的物理分辨率截图（宿主按 displayId 对位 → 按物理原点排序对位）
+  const captures: { display: HostDisplay; origin: { x: number; y: number }; png: PNG }[] = [];
   for (const display of displays) {
     const scale = display.scaleFactor || 1;
     const wantW = Math.round(display.bounds.width * scale);
     const wantH = Math.round(display.bounds.height * scale);
-    const sources = await desktopCapturer.getSources({
-      types: ["screen"],
-      thumbnailSize: { width: wantW, height: wantH }
-    });
-    const source = sources.find(item => item.display_id === String(display.id))
-      || sources.find(item => item.thumbnail.getSize().width === wantW)
-      || sources[0];
-    if (!source || source.thumbnail.isEmpty()) {
-      throw new RuntimeError("desktop_error", "无法获取屏幕截图");
-    }
+    const pngBytes = await screenHost.captureDisplay(display.id, wantW, wantH);
+    if (!pngBytes?.length) throw new RuntimeError("desktop_error", "无法获取屏幕截图");
     // 显示器 DIP 原点的物理坐标 = 该屏物理原点（屏内线性映射: 物理 = (DIP-原点)*缩放 + 物理原点）
-    const origin = screen.dipToScreenPoint({ x: display.bounds.x, y: display.bounds.y });
-    captures.push({ display, origin, png: PNG.sync.read(source.thumbnail.toPNG()) });
+    const origin = screenHost.dipToScreenPoint({ x: display.bounds.x, y: display.bounds.y });
+    captures.push({ display, origin, png: PNG.sync.read(Buffer.from(pngBytes)) });
   }
   const originX = Math.min(...captures.map(c => c.origin.x));
   const originY = Math.min(...captures.map(c => c.origin.y));
@@ -63,9 +56,9 @@ async function captureVirtualScreenPng(): Promise<{ png: PNG; originX: number; o
 
 /** DIP 区域 → 物理像素区域：左上角经 dipToScreenPoint 换算（天然支持副屏/负坐标），宽高乘所在屏缩放比 */
 async function dipRegionToPhysical(region: { x: number; y: number; width: number; height: number }): Promise<{ x: number; y: number; width: number; height: number }> {
-  const { screen } = await import("electron");
-  const topLeft = screen.dipToScreenPoint({ x: Math.round(region.x), y: Math.round(region.y) });
-  const display = screen.getDisplayMatching({
+  const screenHost = requireScreenService();
+  const topLeft = screenHost.dipToScreenPoint({ x: Math.round(region.x), y: Math.round(region.y) });
+  const display = screenHost.displayMatching({
     x: region.x, y: region.y,
     width: Math.max(1, Math.round(region.width)), height: Math.max(1, Math.round(region.height))
   });
@@ -429,7 +422,7 @@ async function locate(args: Record<string, unknown>, evidenceDir: string, nodeId
   const rawAccuracy = Number(text(args, ["accuracy"], "0.8"));
   const similarity = Math.max(0.05, Math.min(1, Number.isFinite(rawAccuracy) && rawAccuracy > 0 ? rawAccuracy : 0.8));
   // 原生 1:1 匹配失败时, 按缩放比对模板放大/缩小重试——兼容旧版 DIP 截图存的模板与任意来源的图片
-  const scale = (await import("electron")).screen.getPrimaryDisplay().scaleFactor || 1;
+  const scale = requireScreenService().primaryDisplay().scaleFactor || 1;
   const result = await findImage(template, screenshot, 1 - similarity, scale !== 1 ? [scale, 1 / scale] : []);
   if (!result) throw new RuntimeError("not_found", `屏幕中未找到目标图像（要求相似度 ${(similarity * 100).toFixed(0)}%，未达到阈值）`, { nodeId, recommendation: "重新框选模板（框小一点、只框目标图案），或适当调低相似度（如 0.8）；目标在副屏时确认其清晰可见" });
   return { ...result, x: result.x + offsetX, y: result.y + offsetY };