Comprehensive bugfix release v1.6.45

Fix ~70 issues across the entire codebase including security fixes,
error handling improvements, test stabilization, and code quality.

- Fix TLS race condition with reference-counted acquire/release
- Bind debug server to 127.0.0.1 instead of 0.0.0.0
- Add overall timeout to MegaWebFallback
- Stream update installer to disk instead of RAM buffering
- Add path traversal protection in JVM extractor
- Cache DdownloadClient with credential-based invalidation
- Add .catch() to all fire-and-forget IPC calls
- Wrap app startup, clipboard, session-log in try/catch
- Add timeouts to container.ts fetch calls
- Fix variable shadowing, tsconfig path, line endings
- Stabilize tests with proper cleanup and timing tolerance
- Fix installer privileges, scripts, and afterPack null checks
- Delete obsolete _upload_release.mjs

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/main/session-log.ts

@@ -76,7 +76,12 @@ async function cleanupOldSessionLogs(dir: string, maxAgeDays: number): Promise<v
 
 export function initSessionLog(baseDir: string): void {
   sessionLogsDir = path.join(baseDir, "session-logs");
-  fs.mkdirSync(sessionLogsDir, { recursive: true });
+  try {
+    fs.mkdirSync(sessionLogsDir, { recursive: true });
+  } catch {
+    sessionLogsDir = null;
+    return;
+  }
 
   const timestamp = formatTimestamp();
   sessionLogPath = path.join(sessionLogsDir, `session_${timestamp}.txt`);