refactor: remove TUI, desktop web UI is now the default and only mode

- Remove internal/tui/ entirely (2600+ lines of Bubble Tea code)
- Remove bubbletea, bubbles, lipgloss direct dependencies
- `muyue` now launches desktop web UI (opens browser)
- CLI subcommands preserved (scan, install, setup, etc.)
- Unknown args passed as desktop flags (--port, --no-open)
- Update help text to reflect new default behavior

💘 Generated with Crush

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

cmd/muyue/main.go

@@ -5,7 +5,6 @@ import (
 	"os"
 	"os/exec"
 
-	tea "github.com/charmbracelet/bubbletea"
 	"github.com/muyue/muyue/internal/config"
 	"github.com/muyue/muyue/internal/desktop"
 	"github.com/muyue/muyue/internal/installer"
@@ -15,26 +14,33 @@ import (
 	"github.com/muyue/muyue/internal/profiler"
 	"github.com/muyue/muyue/internal/scanner"
 	"github.com/muyue/muyue/internal/skills"
-	"github.com/muyue/muyue/internal/tui"
 	"github.com/muyue/muyue/internal/updater"
 	"github.com/muyue/muyue/internal/version"
 )
 
 func main() {
 	if len(os.Args) > 1 {
-		handleCommand(os.Args[1:])
-		return
+		if isCommand(os.Args[1]) {
+			handleCommand(os.Args[1:])
+			return
+		}
 	}
 
-	runTUI()
+	runDesktop(os.Args[1:])
+}
+
+func isCommand(arg string) bool {
+	switch arg {
+	case "version", "-v", "--version",
+		"scan", "install", "update", "setup",
+		"config", "doctor", "lsp", "mcp", "skills",
+		"help", "-h", "--help":
+		return true
+	}
+	return false
 }
 
 func handleCommand(args []string) {
-	if len(args) == 0 {
-		runTUI()
-		return
-	}
-
 	switch args[0] {
 	case "version", "-v", "--version":
 		fmt.Println(version.FullVersion())
@@ -54,16 +60,10 @@ func handleCommand(args []string) {
 		runLSP(args[1:])
 	case "mcp":
 		runMCP(args[1:])
-	case "desktop":
-		runDesktop(args[1:])
 	case "skills":
 		runSkills(args[1:])
 	case "help", "-h", "--help":
 		printHelp()
-	default:
-		fmt.Printf("Unknown command: %s\n", args[0])
-		printHelp()
-		os.Exit(1)
 	}
 }
 
@@ -71,9 +71,13 @@ func printHelp() {
 	fmt.Printf(`%s - AI-powered development environment assistant
 
 Usage:
-  muyue              Start the interactive TUI
+  muyue              Launch desktop app (opens browser)
   muyue <command>    Run a specific command
 
+Options:
+  --port=PORT        Specify port (default: auto)
+  --no-open          Don't open browser automatically
+
 Commands:
   version            Show version
   scan               Scan your system for tools and runtimes
@@ -82,46 +86,17 @@ Commands:
   setup              Run first-time setup wizard
   config             Show current configuration
   doctor             Check that everything is properly configured
-  desktop            Launch desktop web UI (opens browser)
   lsp [scan|install] Scan or install LSP servers
   mcp [config|scan]  Configure MCP servers for Crush and Claude Code
   skills [list|generate|deploy|init|delete] Manage AI coding skills
   help               Show this help
 
-TUI Controls:
-  Ctrl+T             Open tab switcher (navigate with arrows, select with enter)
-  Tab / Shift+Tab    Cycle tabs
-  Ctrl+C             Show quit confirmation (press twice quickly to force quit)
-
-Chat Commands:
-  /plan <goal>       Start a structured Plan→Execute workflow
-
-Workflow Controls:
-  [a]                Approve plan
-  [r]                Reject plan (type feedback)
-  [g]                Generate plan (after answering questions)
-  [n]                Execute next step
-  [x]                Cancel/reset workflow
-
 Note:
   Some tools (docker, gh, etc.) require elevated privileges.
   Run 'sudo muyue install' or use 'pkexec muyue install' if needed.
 `, version.FullVersion())
 }
 
-func runTUI() {
-	cfg := loadOrSetupConfig()
-	result := scanner.ScanSystem()
-
-	model := tui.NewModel(cfg, result)
-	p := tea.NewProgram(model, tea.WithAltScreen())
-
-	if _, err := p.Run(); err != nil {
-		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
-		os.Exit(1)
-	}
-}
-
 func runDesktop(args []string) {
 	cfg := loadOrSetupConfig()
 	if err := desktop.Run(cfg, args); err != nil {