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/mega-web-fallback.ts

@@ -228,22 +228,23 @@ export class MegaWebFallback {
   }
 
   public async unrestrict(link: string, signal?: AbortSignal): Promise<UnrestrictedLink | null> {
+    const overallSignal = withTimeoutSignal(signal, 180000);
     return this.runExclusive(async () => {
-      throwIfAborted(signal);
+      throwIfAborted(overallSignal);
       const creds = this.getCredentials();
       if (!creds.login.trim() || !creds.password.trim()) {
         return null;
       }
 
       if (!this.cookie || Date.now() - this.cookieSetAt > 20 * 60 * 1000) {
-        await this.login(creds.login, creds.password, signal);
+        await this.login(creds.login, creds.password, overallSignal);
       }
 
-      const generated = await this.generate(link, signal);
+      const generated = await this.generate(link, overallSignal);
       if (!generated) {
         this.cookie = "";
-        await this.login(creds.login, creds.password, signal);
-        const retry = await this.generate(link, signal);
+        await this.login(creds.login, creds.password, overallSignal);
+        const retry = await this.generate(link, overallSignal);
         if (!retry) {
           return null;
         }
@@ -261,7 +262,7 @@ export class MegaWebFallback {
         fileSize: null,
         retriesUsed: 0
       };
-    }, signal);
+    }, overallSignal);
   }
 
   public invalidateSession(): void {