feat: 实现 4 个 NAPI 包 — modifiers/image-processor/audio-capture/url-handler

- modifiers-napi: 使用 Bun FFI 调用 macOS CGEventSourceFlagsState 检测修饰键
- image-processor-napi: 集成 sharp 库，macOS 剪贴板图像读取 (osascript)
- audio-capture-napi: 基于 SoX/arecord 的跨平台音频录制
- url-handler-napi: 完善函数签名（保持 null fallback）
- 修复 image-processor 类型兼容性问题

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/image-processor-napi/package.json

@@ -4,5 +4,8 @@
     "private": true,
     "type": "module",
     "main": "./src/index.ts",
-    "types": "./src/index.ts"
+    "types": "./src/index.ts",
+    "dependencies": {
+        "sharp": "^0.33.5"
+    }
 }

packages/image-processor-napi/src/index.ts

@@ -1,6 +1,125 @@
-export function getNativeModule(): null {
+import sharpModule from 'sharp'
+
+export const sharp = sharpModule
+
+interface NativeModule {
+  hasClipboardImage(): boolean
+  readClipboardImage(
+    maxWidth?: number,
+    maxHeight?: number,
+  ): {
+    png: Buffer
+    width: number
+    height: number
+    originalWidth: number
+    originalHeight: number
+  } | null
+}
+
+function createDarwinNativeModule(): NativeModule {
+  return {
+    hasClipboardImage(): boolean {
+      try {
+        const result = Bun.spawnSync({
+          cmd: [
+            'osascript',
+            '-e',
+            'try\nthe clipboard as «class PNGf»\nreturn "yes"\non error\nreturn "no"\nend try',
+          ],
+          stdout: 'pipe',
+          stderr: 'pipe',
+        })
+        const output = result.stdout.toString().trim()
+        return output === 'yes'
+      } catch {
+        return false
+      }
+    },
+
+    readClipboardImage(
+      maxWidth?: number,
+      maxHeight?: number,
+    ) {
+      try {
+        // Use osascript to read clipboard image as PNG data and write to a temp file,
+        // then read the temp file back
+        const tmpPath = `/tmp/claude_clipboard_native_${Date.now()}.png`
+        const script = `
+set png_data to (the clipboard as «class PNGf»)
+set fp to open for access POSIX file "${tmpPath}" with write permission
+write png_data to fp
+close access fp
+return "${tmpPath}"
+`
+        const result = Bun.spawnSync({
+          cmd: ['osascript', '-e', script],
+          stdout: 'pipe',
+          stderr: 'pipe',
+        })
+
+        if (result.exitCode !== 0) {
+          return null
+        }
+
+        const file = Bun.file(tmpPath)
+        // Use synchronous read via Node compat
+        const fs = require('fs')
+        const buffer: Buffer = fs.readFileSync(tmpPath)
+
+        // Clean up temp file
+        try {
+          fs.unlinkSync(tmpPath)
+        } catch {
+          // ignore cleanup errors
+        }
+
+        if (buffer.length === 0) {
+          return null
+        }
+
+        // Read PNG dimensions from IHDR chunk
+        // PNG header: 8 bytes signature, then IHDR chunk
+        // IHDR starts at offset 8 (4 bytes length) + 4 bytes "IHDR" + 4 bytes width + 4 bytes height
+        let width = 0
+        let height = 0
+        if (buffer.length > 24 && buffer[12] === 0x49 && buffer[13] === 0x48 && buffer[14] === 0x44 && buffer[15] === 0x52) {
+          width = buffer.readUInt32BE(16)
+          height = buffer.readUInt32BE(20)
+        }
+
+        const originalWidth = width
+        const originalHeight = height
+
+        // If maxWidth/maxHeight are specified and the image exceeds them,
+        // we still return the full PNG - the caller handles resizing via sharp
+        // But we report the capped dimensions
+        if (maxWidth && maxHeight) {
+          if (width > maxWidth || height > maxHeight) {
+            const scale = Math.min(maxWidth / width, maxHeight / height)
+            width = Math.round(width * scale)
+            height = Math.round(height * scale)
+          }
+        }
+
+        return {
+          png: buffer,
+          width,
+          height,
+          originalWidth,
+          originalHeight,
+        }
+      } catch {
+        return null
+      }
+    },
+  }
+}
+
+export function getNativeModule(): NativeModule | null {
+  if (process.platform === 'darwin') {
+    return createDarwinNativeModule()
+  }
   return null
 }
 
-const stub: any = {}
-export default stub
+export default sharp