release: v2.0.6

Redesign the desktop workspace with task sidebars, live filters, clearer settings, and an accessible update dialog.

Harden encrypted backup imports, configuration persistence, history retention, queue snapshots, shutdown recovery, and update installation ordering.

Publish verified Windows artifacts and refreshed English documentation.

lib/throttled-cache.js

@@ -0,0 +1,51 @@
+// Time-windowed memoization. Reuses a previously-computed value if the
+// signature + input identity match AND the cached entry is younger than
+// `refreshMs`. Used by the renderer's dynamic-key sort throttle (every
+// progress tick re-sorts a 5000-row queue → reuse for 200 ms, the user
+// can't perceive sub-200 ms reorder lag).
+//
+// Loaded both as a CommonJS module (Node tests) and as a browser global
+// (renderer/app.js via index.html script tag) — same single implementation
+// across runtime and tests.
+
+(function (root) {
+  'use strict';
+
+  /**
+   * Build a throttled cache. The clock is injected so tests don't have to
+   * sleep — pass `() => fakeClock.value` from tests.
+   *
+   * @param {number} refreshMs cache TTL in milliseconds
+   * @param {() => number} [now] clock source, defaults to Date.now
+   */
+  function makeThrottledCache(refreshMs, now) {
+    if (!Number.isFinite(refreshMs) || refreshMs < 0) {
+      throw new TypeError('refreshMs must be a non-negative finite number');
+    }
+    const clock = typeof now === 'function' ? now : () => Date.now();
+    let entry = null;
+    return {
+      get(sig, input) {
+        if (!entry) return undefined;
+        if (entry.sig !== sig) return undefined;
+        if (entry.input !== input) return undefined;
+        if (clock() - entry.ts >= refreshMs) return undefined;
+        return entry.value;
+      },
+      set(sig, input, value) {
+        entry = { sig, input, value, ts: clock() };
+        return value;
+      },
+      clear() { entry = null; },
+      // Introspection (mainly for tests/debug). Returns null when empty.
+      peek() {
+        if (!entry) return null;
+        return { sig: entry.sig, ts: entry.ts, age: clock() - entry.ts };
+      }
+    };
+  }
+
+  const api = { makeThrottledCache };
+  if (typeof module !== 'undefined' && module.exports) module.exports = api;
+  else if (root) root.ThrottledCache = api;
+})(typeof window !== 'undefined' ? window : this);