improvements nov2025 (#10)

* Add benchmark and httplog modules, update UI for modals artefacts

internal/httplog/logger.go

@@ -0,0 +1,112 @@
+package httplog
+
+import (
+	"encoding/json"
+	"io"
+	"os"
+	"sync"
+	"time"
+)
+
+// Entry represents a single HTTP log entry
+type Entry struct {
+	Timestamp  time.Time         `json:"timestamp"`
+	ForwardID  string            `json:"forward_id"`
+	RequestID  string            `json:"request_id"`
+	Direction  string            `json:"direction"` // "request" or "response"
+	Method     string            `json:"method,omitempty"`
+	Path       string            `json:"path,omitempty"`
+	StatusCode int               `json:"status_code,omitempty"`
+	Headers    map[string]string `json:"headers,omitempty"`
+	BodySize   int               `json:"body_size"`
+	Body       string            `json:"body,omitempty"`
+	LatencyMs  int64             `json:"latency_ms,omitempty"`
+	Error      string            `json:"error,omitempty"`
+}
+
+// LogCallback is a function that receives log entries
+type LogCallback func(entry Entry)
+
+// Logger writes HTTP log entries to an output stream
+type Logger struct {
+	mu         sync.Mutex
+	output     io.Writer
+	file       *os.File // Only set if we opened the file ourselves
+	forwardID  string
+	maxBodyLen int
+	callbacks  []LogCallback
+}
+
+// NewLogger creates a new HTTP logger
+// If logFile is empty, logs only go to registered callbacks (no file output)
+// This prevents stdout corruption when running in TUI mode
+func NewLogger(forwardID, logFile string, maxBodyLen int) (*Logger, error) {
+	l := &Logger{
+		forwardID:  forwardID,
+		maxBodyLen: maxBodyLen,
+	}
+
+	if logFile == "" {
+		// Don't write to stdout - use io.Discard
+		// Log entries are delivered via callbacks to the UI
+		l.output = io.Discard
+	} else {
+		f, err := os.OpenFile(logFile, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0600)
+		if err != nil {
+			return nil, err
+		}
+		l.file = f
+		l.output = f
+	}
+
+	return l, nil
+}
+
+// AddCallback registers a callback to receive log entries
+func (l *Logger) AddCallback(cb LogCallback) {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	l.callbacks = append(l.callbacks, cb)
+}
+
+// ClearCallbacks removes all registered callbacks
+func (l *Logger) ClearCallbacks() {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	l.callbacks = nil
+}
+
+// Log writes a log entry as JSON
+func (l *Logger) Log(entry Entry) error {
+	entry.ForwardID = l.forwardID
+	entry.Timestamp = time.Now()
+
+	// Truncate body if too large
+	if len(entry.Body) > l.maxBodyLen {
+		entry.Body = entry.Body[:l.maxBodyLen] + "...(truncated)"
+	}
+
+	data, err := json.Marshal(entry)
+	if err != nil {
+		return err
+	}
+
+	l.mu.Lock()
+	defer l.mu.Unlock()
+
+	// Notify callbacks
+	for _, cb := range l.callbacks {
+		cb(entry)
+	}
+
+	_, err = l.output.Write(append(data, '\n'))
+	return err
+}
+
+// Close closes the logger
+func (l *Logger) Close() error {
+	if l.file != nil {
+		return l.file.Close()
+	}
+	return nil
+}