Add hook header generators and CI verification workflow (#597)

.github/workflows/verify-generated-headers.yml

@@ -0,0 +1,36 @@
+name: Verify Generated Hook Headers
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  verify-generated-headers:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - target: hook/error.h
+            generator: ./hook/generate_error.sh
+          - target: hook/extern.h
+            generator: ./hook/generate_extern.sh
+          - target: hook/sfcodes.h
+            generator: bash ./hook/generate_sfcodes.sh
+          - target: hook/tts.h
+            generator: ./hook/generate_tts.sh
+    runs-on: ubuntu-latest
+    name: ${{ matrix.target }}
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Verify ${{ matrix.target }}
+        run: |
+          set -euo pipefail
+          chmod +x hook/generate_*.sh || true
+
+          tmp=$(mktemp)
+          trap 'rm -f "$tmp"' EXIT
+
+          ${{ matrix.generator }} > "$tmp"
+          diff -u ${{ matrix.target }} "$tmp"