Release Twitch VOD Manager 1.0.18

Harden update, system-check, queue, cutter, streamer and shutdown state transitions.

Add multi-user installer recovery, secret-safe config migration, provider fallback handling, managed-tool validation and real media export coverage.

Refresh the English public documentation, release notes and 1.0.18 product screenshot.

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "twitch-vod-manager",
-  "version": "1.0.17",
+  "version": "1.0.18",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "twitch-vod-manager",
-      "version": "1.0.17",
+      "version": "1.0.18",
       "license": "MIT",
       "dependencies": {
         "axios": "^1.16.1",
@@ -4294,9 +4294,9 @@
       "license": "MIT"
     },
     "node_modules/nanoid": {
-      "version": "3.3.17",
-      "resolved": "https://registry.npmjs.org/nanoid/-/nanoid-3.3.17.tgz",
-      "integrity": "sha512-xQLf0A3HOMlgHq0n247/LRuAOYmB7dXJ/DvAxGvsSBij45XtBSmQycu+F8ODbHwns/XyFZagyL1+J0Offw1E0g==",
+      "version": "3.3.18",
+      "resolved": "https://registry.npmjs.org/nanoid/-/nanoid-3.3.18.tgz",
+      "integrity": "sha512-DTg4MJbGMWkfi6VZFdNt2/caMbQy4Ou+Op/hJQvGEWcnVfoA1QA+xzRKAzw9jD6+GVOOeYr/mIcuDSdug6F6+w==",
       "dev": true,
       "funding": [
         {