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>

tests/mega-web-fallback.test.ts

@@ -166,7 +166,7 @@ describe("mega-web-fallback", () => {
       const controller = new AbortController();
       const timer = setTimeout(() => {
         controller.abort("test");
-      }, 30);
+      }, 200);
 
       try {
         await expect(fallback.unrestrict("https://mega.debrid/link2", controller.signal)).rejects.toThrow(/aborted/i);