feat: add --json flag to analyze command for non-TTY environments (#533)

* feat: add --json flag to analyze command

* feat: implement JSON output mode for analyze

* refactor: rename jsonOutput flag to jsonMode to avoid conflict

cmd/analyze/json.go

@@ -0,0 +1,79 @@
+//go:build darwin
+
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"sync/atomic"
+)
+
+type jsonOutput struct {
+	Path       string      `json:"path"`
+	Entries    []jsonEntry `json:"entries"`
+	TotalSize  int64       `json:"total_size"`
+	TotalFiles int64       `json:"total_files"`
+}
+
+type jsonEntry struct {
+	Name  string `json:"name"`
+	Path  string `json:"path"`
+	Size  int64  `json:"size"`
+	IsDir bool   `json:"is_dir"`
+}
+
+func runJSONMode(path string, isOverview bool) {
+	result := performScanForJSON(path)
+
+	encoder := json.NewEncoder(os.Stdout)
+	encoder.SetIndent("", "  ")
+	if err := encoder.Encode(result); err != nil {
+		fmt.Fprintf(os.Stderr, "failed to encode JSON: %v\n", err)
+		os.Exit(1)
+	}
+}
+
+func performScanForJSON(path string) jsonOutput {
+	var filesScanned, dirsScanned, bytesScanned int64
+	currentPath := &atomic.Value{}
+	currentPath.Store("")
+
+	items, err := os.ReadDir(path)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "failed to read directory: %v\n", err)
+		os.Exit(1)
+	}
+
+	var entries []jsonEntry
+	var totalSize int64
+
+	for _, item := range items {
+		fullPath := path + "/" + item.Name()
+		var size int64
+
+		if item.IsDir() {
+			size = calculateDirSizeFast(fullPath, &filesScanned, &dirsScanned, &bytesScanned, currentPath)
+		} else {
+			info, err := item.Info()
+			if err == nil {
+				size = info.Size()
+			}
+		}
+
+		totalSize += size
+		entries = append(entries, jsonEntry{
+			Name:  item.Name(),
+			Path:  fullPath,
+			Size:  size,
+			IsDir: item.IsDir(),
+		})
+	}
+
+	return jsonOutput{
+		Path:       path,
+		Entries:    entries,
+		TotalSize:  totalSize,
+		TotalFiles: filesScanned,
+	}
+}