DEAD-08: add web-SPA entries to knip.json

web.html + src/renderer/web-main.tsx are live via the standalone web
build but were false-flagged. Adding them makes knip runs trustworthy
for later dead-code items.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

electron/knip.json

@@ -8,7 +8,9 @@
     "forge.config.ts",
     "vite.main.config.mts",
     "vite.preload.config.mts",
-    "vite.renderer.config.mts"
+    "vite.renderer.config.mts",
+    "web.html",
+    "src/renderer/web-main.tsx"
   ],
   "ignoreDependencies": [
     "postcss",