ci: add baseline + compat-conformance workflow

withings-export-cli did not have a CI workflow for `go vet` / `go test`
or for the compat-test bundle from quantcli/common. Adding the same
two-job shape used by crono-export-cli (PR
quantcli/crono-export-cli#31): a `go` job that runs `go vet` and
`go test` on every PR, and a `compat` job that builds the binary,
points WITHINGS_EXPORT_BIN at it, and runs
`go test -tags=compat -run TestContractFormats ./...` against the
common-module §4 bundle.

Co-Authored-By: Paperclip <[email protected]>

Author: Terastar-Paperclip

.github/workflows/ci.yml

@@ -0,0 +1,47 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+permissions:
+  contents: read
+
+jobs:
+  go:
+    name: go vet + test
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+          cache: true
+      - name: go vet
+        run: go vet ./...
+      - name: go test
+        run: go test ./...
+
+  compat:
+    name: compat (CONTRACT machine-attestation)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+          cache: true
+      - name: resolve compat dependency
+        # The compat module lives at github.com/quantcli/common/compat
+        # under a subpath. `go mod tidy` materializes go.sum for it on
+        # first run; subsequent runs are cache-served.
+        run: go mod tidy
+      - name: build withings-export
+        run: go build -o /tmp/withings-export .
+      - name: run compat suite
+        env:
+          # Path the compat-tagged test reads from os.Getenv.
+          WITHINGS_EXPORT_BIN: /tmp/withings-export
+        run: go test -tags=compat -run TestContractFormats ./...