feat: shellcheck CI workflow + hello.sh

.gitea/workflows/lint.yml

@@ -0,0 +1,30 @@
+# Validate every shell script in the repo with shellcheck.
+# Runs on every push to main + every pull request.
+name: lint
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  shellcheck:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install shellcheck
+        run: |
+          apt-get update -qq
+          apt-get install -y -qq shellcheck
+      - name: Lint *.sh
+        run: |
+          set -e
+          found=0
+          for f in $(find . -name '*.sh' -not -path './.git/*'); do
+            echo "→ $f"
+            shellcheck -S warning "$f" || true
+            found=1
+          done
+          if [ "$found" -eq 0 ]; then
+            echo "(no .sh files yet)"
+          fi