Bring back some of the CI rules from LayrLabs

Author: aehyvari

.github/workflows/certora-prover.yml

@@ -1,10 +1,22 @@
+name: Certora
+
 on:
+  # Run when PRs from feat/* branches are merged into dev
   pull_request:
+    types: [closed]
     branches:
       - main
+
+  # Run on any pushes to certora/* branches
   push:
     branches:
-      - certora/multichain-specs
+      - 'certora/**'
+
+  # Biweekly schedule (1st and 15th of each month at midnight UTC)
+  schedule:
+    - cron: '0 0 1,15 * *'
+
+  # Manual trigger
   workflow_dispatch:
 
 jobs: