test: guard tests from killing the live dashboard port

Adds a static pretest check and a runtime vitest-setup wrapper that block
shell/process calls matching `kill|pkill|killall|fuser|lsof ... <port>` or
`.listen(<port>)` against reserved Fusion ports. Reserved set is dynamic:
default 4040 plus $PORT, $FUSION_SERVER_PORT, $FUSION_RESERVED_PORTS, and any
port responding to /api/health on 4040..4045 at worker startup.

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

package.json

@@ -14,8 +14,8 @@
   "type": "module",
   "packageManager": "pnpm@10.33.0",
   "scripts": {
-    "pretest": "node scripts/check-no-nohup.mjs",
-    "pretest:full": "node scripts/check-no-nohup.mjs",
+    "pretest": "node scripts/check-no-nohup.mjs && node scripts/check-no-kill-4040.mjs",
+    "pretest:full": "node scripts/check-no-nohup.mjs && node scripts/check-no-kill-4040.mjs",
     "local": "node scripts/start-local.mjs",
     "dev": "node scripts/dev-with-memory.mjs",
     "dev:ui": "pnpm --filter @fusion/dashboard dev",