build: exclude gitignored scripts/lib scratch from scripts typecheck

scripts/lib (local-only dreamer-task/model-dispatch experiment harness) is
gitignored and absent on CI, but the release-time scripts typecheck
(tsc -p tsconfig.scripts.json) was scanning it via scripts/**/*.ts and
failing on local-only drift. Exclude it like scripts/experiments so the
release gate ignores local scratch.

Author: ualtinok

packages/plugin/tsconfig.scripts.json

@@ -16,5 +16,6 @@
         "src/**/*.test.ts",
         "src/**/__tests__/**",
         "scripts/experiments",
+        "scripts/lib",
         "scripts/smoke-node-sqlite.ts"
     ]}