fix: resolve WebSocket connection issues and add connection test script

The WebSocket endpoint /pico/ws was previously blocked by dashboard session
cookie requirements, which often fail on Windows during handshakes.
This change allows /pico/ws to bypass the dashboard middleware and rely
on its own subprotocol-based token authentication.

Also standardizes 'Sec-Websocket-Protocol' casing for Go canonical
header consistency and adds a standalone example script to demonstrate
connecting with an AUTH token.

- Modified web/backend/middleware/launcher_dashboard_auth.go to allow /pico/ws.
- Standardized header casing in pkg/channels/pico/pico.go.
- Added TestPicoChannel_AuthenticateSubprotocol in pkg/channels/pico/pico_test.go.
- Created examples/ws_connect.go for testing and documentation.

Co-authored-by: nglmercer <128845117+nglmercer@users.noreply.github.com>

examples/ws_connect.go

@@ -0,0 +1,60 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+
+	"github.com/gorilla/websocket"
+)
+
+func main() {
+	if len(os.Args) < 3 {
+		fmt.Println("Usage: go run examples/ws_connect.go <ws_url> <token>")
+		fmt.Println("Example: go run examples/ws_connect.go ws://localhost:18800/pico/ws my-secret-token")
+		return
+	}
+
+	wsURL := os.Args[1]
+	token := os.Args[2]
+
+	// The token is passed via the Sec-Websocket-Protocol header as "token.<value>".
+	// This is the standard way to pass an auth token for WebSockets in a browser-compatible way.
+	header := http.Header{}
+	header.Set("Sec-Websocket-Protocol", "token."+token)
+
+	fmt.Printf("Connecting to %s with token...\n", wsURL)
+	dialer := websocket.DefaultDialer
+	conn, resp, err := dialer.Dial(wsURL, header)
+	if err != nil {
+		if resp != nil {
+			log.Fatalf("Handshake failed with status %d: %v", resp.StatusCode, err)
+		}
+		log.Fatalf("Connection failed: %v", err)
+	}
+	defer conn.Close()
+
+	// On success, the server echoes the subprotocol back.
+	fmt.Printf("Connected successfully! Server subprotocol: %s\n", conn.Subprotocol())
+
+	// Send a simple ping message using the Pico protocol format
+	fmt.Println("Sending ping message...")
+	pingMsg := map[string]any{
+		"type": "ping",
+		"id":   "msg-1",
+	}
+	if err := conn.WriteJSON(pingMsg); err != nil {
+		log.Fatalf("Failed to send ping: %v", err)
+	}
+
+	// Read response
+	fmt.Println("Waiting for pong...")
+	var pongMsg map[string]any
+	if err := conn.ReadJSON(&pongMsg); err != nil {
+		log.Fatalf("Failed to read pong: %v", err)
+	}
+
+	fmt.Printf("Received response: %+v\n", pongMsg)
+	fmt.Println("Test completed successfully.")
+}

pkg/channels/pico/pico_test.go

@@ -4,6 +4,8 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"net/http"
+	"strings"
 	"sync"
 	"testing"
 
@@ -142,3 +144,49 @@ func (c *PicoChannel) addConnForTest(pc *picoConn) {
 	}
 	bySession[pc.id] = pc
 }
+
+func TestPicoChannel_AuthenticateSubprotocol(t *testing.T) {
+	cfg := config.PicoConfig{}
+	cfg.SetToken("secret-token")
+	ch, _ := NewPicoChannel(cfg, bus.NewMessageBus())
+
+	tests := []struct {
+		name         string
+		subprotocols []string
+		want         bool
+	}{
+		{
+			name:         "Correct subprotocol",
+			subprotocols: []string{"token.secret-token"},
+			want:         true,
+		},
+		{
+			name:         "Incorrect subprotocol",
+			subprotocols: []string{"token.wrong-token"},
+			want:         false,
+		},
+		{
+			name:         "Multiple subprotocols with correct one",
+			subprotocols: []string{"other-proto", "token.secret-token"},
+			want:         true,
+		},
+		{
+			name:         "No subprotocols",
+			subprotocols: []string{},
+			want:         false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			header := make(http.Header)
+			if len(tt.subprotocols) > 0 {
+				header.Set("Sec-Websocket-Protocol", strings.Join(tt.subprotocols, ", "))
+			}
+			req := &http.Request{Header: header}
+			if got := ch.authenticate(req); got != tt.want {
+				t.Errorf("authenticate() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}