useragent in plc dir reqs

cmd/plcbundle/commands/common.go

···
 	// Create PLC client if URL provided
 	var client *plcclient.Client
 	if opts.PLCURL != "" {
-		client = plcclient.NewClient(opts.PLCURL)
+		// Build user agent with version
+		userAgent := fmt.Sprintf("plcbundle/%s",
+			GetVersion())
+
+		client = plcclient.NewClient(
+			opts.PLCURL,
+			plcclient.WithUserAgent(userAgent),
+		)
 	}
 
 	// Set handle resolver URL from flag or option

internal/plcclient/client.go

···
 	httpClient  *http.Client
 	rateLimiter *RateLimiter
 	logger      Logger
+	userAgent   string
 }
 
 // Logger is a simple logging interface
···
 	}
 }
 
+// WithUserAgent sets a custom user agent string
+func WithUserAgent(userAgent string) ClientOption {
+	return func(c *Client) {
+		c.userAgent = userAgent
+	}
+}
+
 // WithTimeout sets a custom HTTP timeout
 func WithTimeout(timeout time.Duration) ClientOption {
 	return func(c *Client) {
···
 		},
 		rateLimiter: NewRateLimiter(90, time.Minute),
 		logger:      defaultLogger{},
+		userAgent:   "plcbundle/dev",
 	}
 
 	for _, opt := range opts {
···
 	if err != nil {
 		return nil, 0, err
 	}
+	req.Header.Set("User-Agent", c.userAgent)
 
 	// Add query parameters
 	q := req.URL.Query()
···
 	if err != nil {
 		return nil, err
 	}
+	req.Header.Set("User-Agent", c.userAgent)
 
 	resp, err := c.httpClient.Do(req)
 	if err != nil {