ci: add Solhint config and Solidity lint workflow

.github/workflows/solhint.yml

@@ -0,0 +1,37 @@
+name: Solidity Lint (solhint)
+
+on:
+  pull_request:
+    branches: [ ${{ github.event.repository.default_branch || 'main' }} ]
+  push:
+    branches: [ ${{ github.event.repository.default_branch || 'main' }} ]
+
+jobs:
+  solhint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+
+      # Try local devDependency first; fallback to global install
+      - name: Install solhint
+        run: |
+          if [ -f package.json ]; then
+            npm ci || npm i
+            npx --yes solhint --version || npm i -D solhint
+          else
+            npm i -g solhint
+          fi
+
+      - name: Run solhint
+        run: |
+          if ls contracts/**/*.sol >/dev/null 2>&1; then
+            npx solhint 'contracts/**/*.sol' || solhint 'contracts/**/*.sol'
+          else
+            echo "No Solidity files under contracts/, skipping."
+          fi

.solhint.json

@@ -1,18 +1,9 @@
 {
   "extends": "solhint:recommended",
   "rules": {
-    "func-visibility": [
-      "warn",
-      {
-        "ignoreConstructors": true
-      }
-    ],
-    "var-name-mixedcase": "off",
-    "custom-errors": "off",
-    "no-global-import": "off",
-    "reason-string": "off",
-    "no-inline-assembly": "off",
-    "immutable-vars-naming": "off",
-    "one-contract-per-file": "off"
+    "max-line-length": ["warn", 120],
+    "func-visibility": ["error", {"ignoreConstructors": true}],
+    "no-empty-blocks": "warn",
+    "compiler-version": ["error", "^0.8.0"]
   }
 }