feat: 新增mac ocr转文字，增加到问一问微信 图片索引优化速度

- 图片文字索引性能与进度诚实化
- 问问微信：证据卡区分「消息类型」与「派生来源」，派生命中内容自报来源
- 问问微信：回答规则禁止未真实执行的多轮承诺
- 本地图片文字识别：支持 macOS 系统 OCR（Apple Vision）

tests/integration/system-ocr-macos.test.ts

@@ -0,0 +1,131 @@
+// 【macOS】System OCR native fidelity。
+//
+// capability-gated 的原生冒烟测试：只有在「macOS + native 运行时可用」时才真正跑。
+// macOS 的 Apple Vision 后端没有"语言包缺失"这一失败模式，所以门槛只有运行时本身；
+// mock 单元测试仍然是 mandatory（tests/unit/system-ocr-service.test.ts）。
+//
+// 这里断言的是 **macOS 专有**的性质，与 system-ocr-windows.test.ts 刻意不同：
+//   - 引擎标识是 macos-system-ocr；
+//   - 不做任何图片归一化：Vision 原生接受 PNG / JPEG，不得转码、不得起 ffmpeg；
+//   - capability.language 恒为 null（识别语言由 Vision 决定）；
+//   - line.confidence 是 Vision 的真实置信度，不像 Windows 恒为 1.0。
+//
+// fixture 全部是 synthetic 图片（tests/fixtures/ocr/*），不含任何真实聊天数据。
+
+import { readFileSync } from 'node:fs'
+import { join } from 'node:path'
+import { describe, expect, it, vi } from 'vitest'
+import { SYSTEM_OCR_ENGINE_MACOS } from '../../src/shared/system-ocr'
+
+vi.mock('../../src/main/image-decrypt-service', () => ({
+  resolveFfmpegExecutable: (): string => 'ffmpeg'
+}))
+
+import { SystemOcrService, systemOcrService } from '../../src/main/services/system-ocr-service'
+
+const fixtureDirectory = join(__dirname, '..', 'fixtures', 'ocr')
+
+const toDataUrl = (fileName: string, mimeType: string): string =>
+  `data:${mimeType};base64,${readFileSync(join(fixtureDirectory, fileName)).toString('base64')}`
+
+/** 只比较"主要 token"，避免识别微差造成脆弱测试。 */
+const expectContainsTokens = (text: string, tokens: string[]): void => {
+  const normalized = text.replace(/[\s\u3000]+/g, '').toLowerCase()
+  for (const token of tokens) {
+    expect(normalized).toContain(token.replace(/[\s\u3000]+/g, '').toLowerCase())
+  }
+}
+
+const capability = await systemOcrService.getCapability()
+const onMac = process.platform === 'darwin'
+const platformGate = onMac ? it : it.skip
+const nativeGate = onMac && capability.available ? it : it.skip
+
+/**
+ * 走「真实 process.platform/arch + 真实 native binding + 默认归一化路径」的实例，
+ * 只把 ffmpeg 解析器换成 spy —— 用来证明 macOS 路径根本没有碰归一化。
+ */
+const ffmpegResolver = vi.fn(() => 'ffmpeg')
+const nativeService = new SystemOcrService({ resolveFfmpegExecutable: ffmpegResolver })
+
+describe('macOS System OCR native fidelity', () => {
+  platformGate('reports a usable capability backed by Apple Vision', () => {
+    expect(capability.engine).toBe(SYSTEM_OCR_ENGINE_MACOS)
+    expect(capability.platform).toBe('darwin')
+    expect(capability.runtimeVersion).not.toBeNull()
+    // Vision 自行决定识别语言，不声称任何语言包。
+    expect(capability.language).toBeNull()
+    if (!capability.available) {
+      console.warn(`[integration] macOS System OCR smoke skipped: ${capability.message}`)
+    }
+  })
+
+  nativeGate('recognizes simplified Chinese text', async () => {
+    const result = await nativeService.recognize({
+      imageDataUrl: toDataUrl('system-ocr-zh.png', 'image/png')
+    })
+    expect(result.success).toBe(true)
+    expectContainsTokens(result.text, ['TraceMemo', '本地', '文字', '识别'])
+    expect(result.language).toBeNull()
+    expect(result.durationMs).toBeGreaterThan(0)
+  })
+
+  nativeGate('recognizes English text', async () => {
+    const result = await nativeService.recognize({
+      imageDataUrl: toDataUrl('system-ocr-en.png', 'image/png')
+    })
+    expect(result.success).toBe(true)
+    expectContainsTokens(result.text, ['TraceMemo', 'System', 'OCR'])
+  })
+
+  nativeGate('recognizes mixed Chinese/English text', async () => {
+    const result = await nativeService.recognize({
+      imageDataUrl: toDataUrl('system-ocr-mixed.png', 'image/png')
+    })
+    expect(result.success).toBe(true)
+    expectContainsTokens(result.text, ['TraceMemo', '本地', 'OCR', '2026'])
+  })
+
+  /**
+   * Vision 原生接受 JPEG —— 这条用例同时是「macOS 不做归一化」的回归保护：
+   * 一旦有人把 Windows 的 PNG-only 假设搬过来，ffmpeg 解析器就会被调用。
+   */
+  nativeGate('accepts JPEG directly without any image normalization', async () => {
+    ffmpegResolver.mockClear()
+    const result = await nativeService.recognize({
+      imageDataUrl: toDataUrl('system-ocr-mixed.jpg', 'image/jpeg')
+    })
+    expect(result.success).toBe(true)
+    expectContainsTokens(result.text, ['TraceMemo', 'OCR', '2026'])
+    expect(ffmpegResolver).not.toHaveBeenCalled()
+  })
+
+  nativeGate('reports real Vision confidence and top-left-origin boxes', async () => {
+    const result = await nativeService.recognize({
+      imageDataUrl: toDataUrl('system-ocr-mixed.png', 'image/png')
+    })
+    expect(result.success).toBe(true)
+    expect(result.lines.length).toBeGreaterThan(0)
+    for (const line of result.lines) {
+      // Windows 恒为 1.0；macOS 必须给出真实置信度。
+      expect(line.confidence).toBeGreaterThanOrEqual(0)
+      expect(line.confidence).toBeLessThanOrEqual(1)
+      const { x, y, width, height } = line.boundingBox
+      for (const value of [x, y, width, height]) {
+        expect(Number.isFinite(value)).toBe(true)
+      }
+      expect(x).toBeGreaterThanOrEqual(0)
+      expect(y).toBeGreaterThanOrEqual(0)
+      expect(x + width).toBeLessThanOrEqual(1.0001)
+      expect(y + height).toBeLessThanOrEqual(1.0001)
+    }
+  })
+
+  nativeGate('caches an identical repeat request', async () => {
+    const request = { imageDataUrl: toDataUrl('system-ocr-en.png', 'image/png') }
+    const first = await systemOcrService.recognize(request)
+    const second = await systemOcrService.recognize(request)
+    expect(first.success).toBe(true)
+    expect(second.fromCache).toBe(true)
+  })
+})