ci: add proof-hash workflow to generate and upload SHA256SUMS

Author: DONSystemsLLC

.github/workflows/proof-hash.yml

@@ -0,0 +1,34 @@
+name: Proof Bundle Hashes
+
+on:
+  pull_request:
+    paths:
+      - 'proofs/**'
+      - 'tools/hash_bundle.py'
+
+jobs:
+  hash:
+    name: Generate and Upload SHA256SUMS
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 1
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.x'
+
+      - name: Run proof hasher
+        run: |
+          python tools/hash_bundle.py
+
+      - name: Upload SHA256SUMS.txt artifacts
+        uses: actions/upload-artifact@v4
+        with:
+          name: proof-hashes
+          path: |
+            proofs/**/SHA256SUMS.txt
+          if-no-files-found: ignore