Clean project layout and fix release workflow

internal/app/runtime.go

@@ -26,18 +26,50 @@ func (w *runtimeLogWriter) Write(p []byte) (int, error) {
 	return w.file.Write(p)
 }
 
+func (w *runtimeLogWriter) ensureFile(path string) error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	if w.file != nil {
+		return nil
+	}
+	f, err := os.OpenFile(path, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0o644)
+	if err != nil {
+		return err
+	}
+	w.file = f
+	return nil
+}
+
+func (w *runtimeLogWriter) appendf(path, format string, args ...any) error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	if w.file == nil {
+		f, err := os.OpenFile(path, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0o644)
+		if err != nil {
+			return err
+		}
+		w.file = f
+	}
+	_, err := fmt.Fprintf(w.file, format, args...)
+	return err
+}
+
+var runtimeLogFileWriter runtimeLogWriter
+var joinLeaveLogFileWriter runtimeLogWriter
+var desktopJoinLogMu sync.Mutex
+var desktopJoinLogLastPath string
+var desktopJoinLogLastBody string
+
 func setupRuntimeLogger() error {
 	dir := filepath.Join(common.RootDir(), "runtime")
 	if err := os.MkdirAll(dir, 0o755); err != nil {
 		return err
 	}
 	path := filepath.Join(dir, "runtime.log")
-	f, err := os.OpenFile(path, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0o644)
-	if err != nil {
+	if err := runtimeLogFileWriter.ensureFile(path); err != nil {
 		return err
 	}
-	logWriter := &runtimeLogWriter{file: f}
-	log.SetOutput(io.MultiWriter(os.Stderr, logWriter))
+	log.SetOutput(io.MultiWriter(os.Stderr, &runtimeLogFileWriter))
 	return nil
 }
 
@@ -51,13 +83,7 @@ func appendRuntimeLog(title, text string) error {
 	if body == "" {
 		body = "(empty)"
 	}
-	f, err := os.OpenFile(path, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0o644)
-	if err != nil {
-		return err
-	}
-	defer f.Close()
-	_, err = fmt.Fprintf(f, "\n[%s] %s\n%s\n", time.Now().Format("2006-01-02 15:04:05"), title, body)
-	return err
+	return runtimeLogFileWriter.appendf(path, "\n[%s] %s\n%s\n", time.Now().Format("2006-01-02 15:04:05"), title, body)
 }
 
 func AppendRuntimeLog(title, text string) error {
@@ -74,13 +100,7 @@ func appendJoinLeaveLog(text string) error {
 	if body == "" {
 		body = "(empty)"
 	}
-	f, err := os.OpenFile(path, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0o644)
-	if err != nil {
-		return err
-	}
-	defer f.Close()
-	_, err = fmt.Fprintf(f, "\n[%s] VRC JOIN/LEAVE\n%s\n", time.Now().Format("2006-01-02 15:04:05"), body)
-	return err
+	return joinLeaveLogFileWriter.appendf(path, "\n[%s] VRC JOIN/LEAVE\n%s\n", time.Now().Format("2006-01-02 15:04:05"), body)
 }
 
 func appendDesktopJoinLog(title, worldLabel, text string) error {
@@ -101,6 +121,11 @@ func appendDesktopJoinLog(title, worldLabel, text string) error {
 	if body == "" {
 		body = "(empty)"
 	}
+	desktopJoinLogMu.Lock()
+	defer desktopJoinLogMu.Unlock()
+	if desktopJoinLogLastPath == path && desktopJoinLogLastBody == body {
+		return nil
+	}
 	f, err := os.OpenFile(path, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0o644)
 	if err != nil {
 		fallbackDir := filepath.Join(common.RootDir(), "runtime")
@@ -115,8 +140,12 @@ func appendDesktopJoinLog(title, worldLabel, text string) error {
 		path = fallbackPath
 	}
 	defer f.Close()
-	_, err = fmt.Fprintf(f, "%s\nWorld: %s\n\n%s\n", title, worldLabel, body)
-	return err
+	if _, err = fmt.Fprintf(f, "%s\n", body); err != nil {
+		return err
+	}
+	desktopJoinLogLastPath = path
+	desktopJoinLogLastBody = body
+	return nil
 }
 
 func AppendDesktopJoinLog(title, worldLabel, text string) error {