fix: update build scripts to use pnpm filter for monorepo

Update build:custom-node and build:sea scripts to delegate to their respective packages using pnpm --filter. This fixes the broken scripts that were pointing to the old pre-monorepo file locations.

The -- at the end enables flag forwarding to the underlying build scripts.

Author: jdalton

package.json

@@ -180,8 +180,8 @@
     "build": "pnpm --filter \"./packages/**\" run build",
     "build:cli": "pnpm --filter @socketsecurity/cli run build",
     "build:socket": "pnpm --filter socket run build",
-    "build:custom-node": "node scripts/build-custom-node.mjs",
-    "build:sea": "node scripts/build-sea.mjs",
+    "build:custom-node": "pnpm --filter @socketbin/custom-node run build --",
+    "build:sea": "pnpm --filter @socketbin/sea run build --",
     "check": "pnpm --filter @socketsecurity/cli run check",
     "check-ci": "pnpm --filter @socketsecurity/cli run check-ci",
     "clean": "pnpm --filter \"./packages/**\" run clean",