feat: Go 图片识别 CLI 工具 — 对接 Agnes-2.0-Flash 免费视觉模型

为 Claude Code 等 AI 编码助手提供图片理解能力：
- 支持本地图片 base64 编码上传
- 多图对比分析
- 自动重试 + 指数退避
- 多源配置管理（命令行/环境变量/配置文件）
- 关闭 thinking 模式以降低延迟

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

main.go

@@ -0,0 +1,118 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+func main() {
+	// Command-line flags
+	var (
+		apiKey     string
+		configPath string
+		prompt     string
+		quiet      bool
+		noThink    bool
+		saveConfig bool
+	)
+
+	flag.StringVar(&apiKey, "apikey", "", "Zhipu AI API key (or set ZHIPU_API_KEY env var)")
+	flag.StringVar(&configPath, "config", "", "Path to config.json file")
+	flag.StringVar(&prompt, "prompt", "", "Custom prompt for image analysis")
+	flag.BoolVar(&quiet, "q", false, "Quiet mode — only output the model's response text")
+	flag.BoolVar(&noThink, "no-think", false, "Disable thinking mode (faster, lower server load)")
+	flag.BoolVar(&saveConfig, "save-config", false, "Save the API key to config.json and exit")
+	flag.Parse()
+
+	// Handle --save-config: persist the key and exit
+	if saveConfig {
+		if apiKey == "" {
+			fmt.Fprintln(os.Stderr, "Error: --apikey is required with --save-config")
+			os.Exit(1)
+		}
+		if configPath == "" {
+			configPath = filepath.Join(getToolsDir(), "config.json")
+		}
+		if err := SaveConfigFile(configPath, apiKey); err != nil {
+			fmt.Fprintf(os.Stderr, "Failed to save config: %v\n", err)
+			os.Exit(1)
+		}
+		fmt.Printf("API key saved to %s\n", configPath)
+		return
+	}
+
+	// Load configuration
+	cfg, err := LoadConfig(apiKey, configPath)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+
+	if !quiet {
+		fmt.Fprintf(os.Stderr, "Using model: %s | API key: %s\n", cfg.Model, MaskKey(cfg.APIKey))
+	}
+
+	// Collect image paths from remaining args
+	imagePaths := flag.Args()
+	if len(imagePaths) == 0 {
+		fmt.Fprintln(os.Stderr, "Usage: vision-tool [flags] <image-file> [image-file2 ...]")
+		fmt.Fprintln(os.Stderr, "")
+		fmt.Fprintln(os.Stderr, "Flags:")
+		flag.PrintDefaults()
+		fmt.Fprintln(os.Stderr, "")
+		fmt.Fprintln(os.Stderr, "Examples:")
+		fmt.Fprintln(os.Stderr, "  vision-tool photo.jpg")
+		fmt.Fprintln(os.Stderr, "  vision-tool -prompt \"这张图里有什么文字？\" screenshot.png")
+		fmt.Fprintln(os.Stderr, "  vision-tool -q img1.png img2.png")
+		fmt.Fprintln(os.Stderr, "  vision-tool --apikey YOUR_KEY photo.jpg")
+		fmt.Fprintln(os.Stderr, "  vision-tool --save-config --apikey YOUR_KEY")
+		os.Exit(1)
+	}
+
+	// Validate image files exist
+	for _, p := range imagePaths {
+		if _, err := os.Stat(p); os.IsNotExist(err) {
+			fmt.Fprintf(os.Stderr, "Error: file not found: %s\n", p)
+			os.Exit(1)
+		}
+	}
+
+	client := NewVisionClient(cfg, noThink)
+
+	if !quiet {
+		fmt.Fprintf(os.Stderr, "Analyzing %d image(s)...\n\n", len(imagePaths))
+	}
+
+	// Call the API
+	var resp *ChatResponse
+	if len(imagePaths) == 1 {
+		resp, err = client.AnalyzeImage(imagePaths[0], prompt)
+	} else {
+		resp, err = client.AnalyzeImages(imagePaths, prompt)
+	}
+
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+
+	// Output the result
+	if len(resp.Choices) > 0 {
+		fmt.Println(resp.Choices[0].Message.Content)
+	}
+
+	if resp.Usage != nil && !quiet {
+		fmt.Fprintf(os.Stderr, "\n---\nTokens: prompt=%d completion=%d total=%d\n",
+			resp.Usage.PromptTokens, resp.Usage.CompletionTokens, resp.Usage.TotalTokens)
+	}
+}
+
+func getToolsDir() string {
+	exe, err := os.Executable()
+	if err != nil {
+		return "."
+	}
+	return filepath.Dir(exe)
+}