Fix logger not capturing crash logs

The logging system was losing logs during crashes because:
1. Async writes via queueMicrotask weren't completing before process exit
2. uncaughtException/unhandledRejection handlers didn't flush logs
3. No exit handler to catch all exit paths

Changes:
- Add flushSync() method for synchronous writes
- Make Logger.shutdown() flush synchronously
- Call Logger.shutdown() in crash handlers (uncaughtException, unhandledRejection)
- Add process.on("exit") as final safety net

Now all logs are guaranteed to be written before the process exits, making crash debugging actually possible.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: statico

src/index.ts

@@ -52,13 +52,19 @@ truncateLogIfNeeded();
 
 process.on("uncaughtException", (error) => {
   logError("UNCAUGHT EXCEPTION", error);
+  Logger.error("Process", "Uncaught exception", error);
+  Logger.shutdown();
   console.error("Fatal error:", error.message);
   console.error(`Stack trace saved to ${ERROR_LOG_PATH}`);
   process.exit(1);
 });
 
 process.on("unhandledRejection", (reason) => {
   logError("UNHANDLED REJECTION", reason);
+  Logger.error("Process", "Unhandled rejection", reason instanceof Error ? reason : undefined, {
+    reason: String(reason)
+  });
+  Logger.shutdown();
   console.error("Unhandled promise rejection:", reason);
   process.exit(1);
 });
@@ -81,6 +87,11 @@ process.on("SIGHUP", () => {
   process.exit(0);
 });
 
+// Final safety net - flush logs on any exit
+process.on("exit", (code) => {
+  Logger.shutdown();
+});
+
 // Parse CLI arguments
 const args = process.argv.slice(2);
 let address = "192.168.0.123";

src/logger.ts

@@ -56,7 +56,12 @@ class Logger {
   static shutdown(): void {
     if (Logger.instance) {
       Logger.instance.stopFlushTimer();
-      Logger.instance.flushNow();
+      // Flush synchronously to ensure logs are written before exit
+      if (Logger.instance.writeQueue.length > 0) {
+        const entries = Logger.instance.writeQueue.join("");
+        Logger.instance.writeQueue = [];
+        Logger.instance.flushSync(entries);
+      }
       Logger.instance = null;
     }
   }
@@ -102,16 +107,20 @@ class Logger {
     this.writeQueue = [];
 
     queueMicrotask(() => {
-      try {
-        appendFileSync(LOG_PATH, entries);
-        this.rotateLogIfNeeded();
-      } catch (error) {
-        // Can't log errors in the logger, just output to console
-        console.error("Failed to write log:", error);
-      }
+      this.flushSync(entries);
     });
   }
 
+  private flushSync(entries: string): void {
+    try {
+      appendFileSync(LOG_PATH, entries);
+      this.rotateLogIfNeeded();
+    } catch (error) {
+      // Can't log errors in the logger, just output to console
+      console.error("Failed to write log:", error);
+    }
+  }
+
   private rotateLogIfNeeded(): void {
     try {
       if (!existsSync(LOG_PATH)) return;