release: 5.1.0-alpha.0 - integrity-check + archive-files-store + format-helpers

Continuation post-5.0.0. Adds three more domain/infra modules + 46 tests
(210 total). Touched pillars:

- Pillar 1 (Live-Rec): integrity-check ffprobe parser + verdict
- Pillar 6 (Smart-Resume / Archive): archive-files-store CRUD + summary
- Pillar 4 (Architecture-Split): format-helpers extraction (4 more pure
  functions out of main.ts: sanitizeFilenamePart, formatTwitchDurationFromSeconds,
  formatDateWithPattern, getMergeGroupPhaseText)

main.ts continues to shrink (now ~7160 LoC from 7485 start). Renderer-side
work (Pillar 5 UI Power) + recorder integration (Plan 04b) + OAuth IPC
wiring (needs Twitch Client ID from user) still ahead.

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

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "twitch-vod-manager",
-  "version": "5.0.0",
+  "version": "5.1.0-alpha.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "twitch-vod-manager",
-      "version": "5.0.0",
+      "version": "5.1.0-alpha.0",
       "license": "MIT",
       "dependencies": {
         "axios": "^1.6.0",

package.json

@@ -1,6 +1,6 @@
 {
   "name": "twitch-vod-manager",
-  "version": "5.0.0",
+  "version": "5.1.0-alpha.0",
   "description": "Twitch VOD Manager - Download Twitch VODs easily",
   "main": "dist/main.js",
   "author": "xRangerDE",