feat: add Cobra CLI, LSP/MCP registries, workflow engine, and enriched dashboard

Major changes:
- Refactor CLI entry point to Cobra commands (root, setup, scan, doctor, install, update, lsp, mcp, skills, config, version)
- Add LSP registry with health checks, auto-install, and editor config generation
- Add MCP registry with editor detection, status tracking, and per-editor configuration
- Add workflow engine with planner and step execution for automated task chains
- Add conversation search, export (Markdown/JSON), and detailed token counting
- Add streaming shell chat handler with tool call/result events
- Add skill validation, dry-run testing, and export endpoints
- Enrich dashboard with Tools/Activity/Status tabs and tool cards grid
- Add PRD documentation
- Complete i18n for both EN and FR

💘 Generated with Crush

Assisted-by: GLM-5.1 via Crush <crush@charm.land>

cmd/muyue/commands/scan.go

@@ -0,0 +1,56 @@
+package commands
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/muyue/muyue/internal/scanner"
+	"github.com/spf13/cobra"
+)
+
+var scanCmd = &cobra.Command{
+	Use:   "scan",
+	Short: "Run system scan and print results table",
+	RunE:  runScan,
+}
+
+func init() {
+	rootCmd.AddCommand(scanCmd)
+	scanCmd.Flags().Bool("json", false, "Output results as JSON")
+}
+
+func runScan(cmd *cobra.Command, args []string) error {
+	useJSON, _ := cmd.Flags().GetBool("json")
+	result := scanner.ScanSystem()
+
+	if useJSON {
+		data, err := json.MarshalIndent(result, "", "  ")
+		if err != nil {
+			return err
+		}
+		fmt.Println(string(data))
+		return nil
+	}
+
+	fmt.Printf("%-15s %-20s %-10s %-10s\n", "Tool", "Version", "Status", "Path")
+	fmt.Println("─────────────────────────────────────────────────")
+	for _, t := range result.Tools {
+		status := "✓ installed"
+		if !t.Installed {
+			status = "✗ missing"
+		}
+		fmt.Printf("%-15s %-20s %-10s %-10s\n", t.Name, t.Version, status, t.Path)
+	}
+	fmt.Printf("\n%  d/%d tools installed\n", len(result.Tools) - countMissing(result.Tools), len(result.Tools))
+	return nil
+}
+
+func countMissing(tools []scanner.ToolStatus) int {
+	missing := 0
+	for _, t := range tools {
+		if !t.Installed {
+			missing++
+		}
+	}
+	return missing
+}