chore: bump version to 0.3.0

feat(shell): real terminal with xterm.js + PTY over WebSocket

Replace fake shell input with a full PTY-backed terminal using xterm.js.
Apps like btop, vim, htop now work. AI chat panel is always visible.

Backend:
- Add WebSocket handler /api/ws/terminal with creack/pty
- Allocate real pseudo-terminal with TERM=xterm-256color
- Bidirectional I/O + dynamic resize via pty.Setsize
- Skip JSON headers on /api/ws/* paths for WebSocket upgrade

Frontend:
- Integrate xterm.js with FitAddon and WebLinksAddon
- Cyberpunk color theme matching app design
- ResizeObserver for automatic terminal resizing
- AI assistant panel always visible (340px, no toggle)
- Connection status indicator (green/red dot)

Dependencies:
- Go: github.com/gorilla/websocket, github.com/creack/pty/v2
- npm: @xterm/xterm, @xterm/addon-fit, @xterm/addon-web-links

💘 Generated with Crush

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

internal/api/terminal.go

@@ -0,0 +1,120 @@
+package api
+
+import (
+	"encoding/json"
+	"log"
+	"net/http"
+	"os"
+	"os/exec"
+	"sync"
+	"time"
+
+	"github.com/creack/pty/v2"
+	"github.com/gorilla/websocket"
+)
+
+var upgrader = websocket.Upgrader{
+	CheckOrigin: func(r *http.Request) bool { return true },
+}
+
+type wsMessage struct {
+	Type string `json:"type"`
+	Data string `json:"data"`
+	Rows uint16 `json:"rows,omitempty"`
+	Cols uint16 `json:"cols,omitempty"`
+}
+
+func (s *Server) handleTerminalWS(w http.ResponseWriter, r *http.Request) {
+	conn, err := upgrader.Upgrade(w, r, nil)
+	if err != nil {
+		log.Printf("ws upgrade: %v", err)
+		return
+	}
+	defer conn.Close()
+
+	shell := "/bin/sh"
+	if s, err := exec.LookPath("bash"); err == nil {
+		shell = s
+	}
+
+	cmd := exec.Command(shell)
+	cmd.Env = append(os.Environ(), "TERM=xterm-256color")
+
+	ptmx, err := pty.Start(cmd)
+	if err != nil {
+		log.Printf("pty start: %v", err)
+		conn.WriteJSON(wsMessage{Type: "error", Data: err.Error()})
+		return
+	}
+	defer func() {
+		ptmx.Close()
+		if cmd.Process != nil {
+			cmd.Process.Kill()
+			cmd.Wait()
+		}
+	}()
+
+	var once sync.Once
+	cleanup := func() {
+		once.Do(func() {
+			ptmx.Close()
+			if cmd.Process != nil {
+				cmd.Process.Kill()
+				cmd.Wait()
+			}
+		})
+	}
+
+	// PTY -> WebSocket
+	go func() {
+		buf := make([]byte, 4096)
+		for {
+			n, err := ptmx.Read(buf)
+			if err != nil {
+				cleanup()
+				conn.WriteMessage(websocket.CloseMessage,
+					websocket.FormatCloseMessage(websocket.CloseNormalClosure, ""))
+				return
+			}
+			if err := conn.WriteJSON(wsMessage{
+				Type: "output",
+				Data: string(buf[:n]),
+			}); err != nil {
+				cleanup()
+				return
+			}
+		}
+	}()
+
+	// WebSocket -> PTY
+	conn.SetReadLimit(1 << 20) // 1MB
+	conn.SetReadDeadline(time.Time{})
+
+	for {
+		_, raw, err := conn.ReadMessage()
+		if err != nil {
+			cleanup()
+			return
+		}
+
+		var msg wsMessage
+		if err := json.Unmarshal(raw, &msg); err != nil {
+			continue
+		}
+
+		switch msg.Type {
+		case "input":
+			if _, err := ptmx.Write([]byte(msg.Data)); err != nil {
+				cleanup()
+				return
+			}
+		case "resize":
+			if msg.Rows > 0 && msg.Cols > 0 {
+				pty.Setsize(ptmx, &pty.Winsize{
+					Rows: msg.Rows,
+					Cols: msg.Cols,
+				})
+			}
+		}
+	}
+}