ci(checks): add pull request workflow and golangci-lint config

.github/workflows/ci.yml

@@ -0,0 +1,38 @@
+name: CI
+
+on:
+  pull_request:
+    branches: [master]
+
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+
+      - name: Build
+        run: go build ./...
+
+      - name: Vet
+        run: go vet ./...
+
+      - name: Format check
+        run: |
+          unformatted=$(gofmt -l $(go list -f '{{.Dir}}' ./...))
+          if [ -n "$unformatted" ]; then
+            echo "These files need gofmt:"
+            echo "$unformatted"
+            exit 1
+          fi
+
+      - name: Lint
+        uses: golangci/golangci-lint-action@v7
+        with:
+          version: v2.4.0
+
+      - name: Test (race detector)
+        run: go test -race ./...

.golangci.yml

@@ -0,0 +1,16 @@
+version: "2"
+
+run:
+  timeout: 5m
+
+linters:
+  default: none
+  enable:
+    - errcheck
+    - govet
+    - ineffassign
+    - staticcheck
+    - unused
+  exclusions:
+    paths:
+      - terminal-shop-source