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/install.go

@@ -0,0 +1,56 @@
+package commands
+
+import (
+	"fmt"
+
+	"github.com/muyue/muyue/internal/installer"
+	"github.com/muyue/muyue/internal/scanner"
+	"github.com/spf13/cobra"
+)
+
+var installCmd = &cobra.Command{
+	Use:   "install [tool]",
+	Short: "Install missing tools",
+	Args:  cobra.RangeArgs(0, 1),
+	RunE:  runInstall,
+}
+
+var installYes bool
+
+func init() {
+	rootCmd.AddCommand(installCmd)
+	installCmd.Flags().BoolVar(&installYes, "yes", false, "Skip confirmation")
+}
+
+func runInstall(cmd *cobra.Command, args []string) error {
+	var tools []string
+	if len(args) > 0 {
+		tools = args
+	}
+
+	inst := installer.New(nil)
+	if len(tools) == 0 {
+		result := scanner.ScanSystem()
+		for _, t := range result.Tools {
+			if !t.Installed {
+				tools = append(tools, t.Name)
+			}
+		}
+		if len(tools) == 0 {
+			fmt.Println("All tools already installed!")
+			return nil
+		}
+		fmt.Printf("Installing missing tools: %v\n", tools)
+	}
+
+	for _, tool := range tools {
+		fmt.Printf("Installing %s...\n", tool)
+		res := inst.InstallTool(tool)
+		if res.Success {
+			fmt.Printf("✓ %s: %s\n", tool, res.Message)
+		} else {
+			fmt.Printf("✗ %s: %s\n", tool, res.Message)
+		}
+	}
+	return nil
+}