release: v2.1.12 reliability and security hardening

Verify update artifacts with exact metadata and SHA-512, require host-confirmed upload completion before cleanup, harden credentials and backups, improve queue recovery and skipped-state reporting, expand Windows path coverage, and add CI packaging checks.

tests/history-status.test.js

@@ -0,0 +1,17 @@
+const test = require('node:test');
+const assert = require('node:assert/strict');
+
+const { classifyHistoryStatus, historyDetail } = require('../renderer/history-status');
+
+test('history status keeps skipped separate from successful and failed uploads', () => {
+  assert.equal(classifyHistoryStatus('done'), 'success');
+  assert.equal(classifyHistoryStatus('error'), 'error');
+  assert.equal(classifyHistoryStatus('aborted'), 'error');
+  assert.equal(classifyHistoryStatus('skipped'), 'skipped');
+  assert.equal(classifyHistoryStatus('unexpected'), 'error');
+});
+
+test('history detail shows a skipped reason instead of a fake link', () => {
+  assert.equal(historyDetail({ status: 'skipped', error: 'Datei zu groß', download_url: 'https://example.invalid/wrong' }), 'Datei zu groß');
+  assert.equal(historyDetail({ status: 'done', download_url: 'https://example.invalid/ok' }), 'https://example.invalid/ok');
+});