release: 4.5.8 fsync atomic writes, parallel filename race, UI persistence

Stability + UX cycle.

- saveConfig and writeQueueToDisk now use openSync+writeSync+fsyncSync+
  closeSync+renameSync via writeFileAtomicSync. Survives power loss
  between write and rename (used to leave the renamed file empty and
  silently reset config / queue on next launch).
- Per-item claimedFilenames map fixes the parallel-download race where
  one item finishing wiped sibling claims and let a third item collide
  on the same output path.
- Renderer queue lookup by [data-id] (no more index drift), active tab
  persisted in localStorage, Escape closes the topmost open modal,
  Ctrl/Cmd+1..5 jumps tabs.

See docs/IMPROVEMENT_LOG.md for the dated rationale and regression run.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "twitch-vod-manager",
-  "version": "4.5.7",
+  "version": "4.5.8",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "twitch-vod-manager",
-      "version": "4.5.7",
+      "version": "4.5.8",
       "license": "MIT",
       "dependencies": {
         "axios": "^1.6.0",

package.json

@@ -1,6 +1,6 @@
 {
   "name": "twitch-vod-manager",
-  "version": "4.5.7",
+  "version": "4.5.8",
   "description": "Twitch VOD Manager - Download Twitch VODs easily",
   "main": "dist/main.js",
   "author": "xRangerDE",