chore(ci): add race detector and coverage reporting to PR workflow

Enable -race flag and coverage profiling in CI test step.
Add coverage summary output. Update .gitignore for IDE dirs.

.github/workflows/pr.yml

@@ -47,6 +47,9 @@ jobs:
         with:
           go-version-file: go.mod
 
-      - name: Run go test
-        run: go test ./...
+      - name: Run go test with race detector
+        run: go test -race -coverprofile=coverage.txt -covermode=atomic ./...
 
+      - name: Print coverage summary
+        if: always()
+        run: go tool cover -func=coverage.txt | tail -1

.gitignore

@@ -35,4 +35,8 @@ coverage.html
 # Ralph workspace
 ralph/
 .ralph/
-tasks/
+tasks/
+
+# IDE
+.vscode/
+.cursor/