test: stabilize poll latency and refresh dependencies

[taigrr]

Summary

• keep the strict 3ms poll latency threshold for normal test runs
• detect the Go race build tag in tests and allow a higher threshold under -race
• update the CI Staticcheck module pin to v0.8.1 so it can read current Go export data
• update the module directive to Go 1.27.1 and refresh terminal-related dependencies

Validation

• go generate ./...
• go test ./...
• go test -race ./...
• go vet ./...
• staticcheck ./...
• go build ./...
• go mod tidy -diff
• go run honnef.co/go/tools/cmd/staticcheck@v0.8.1 ./...
• go run golang.org/x/vuln/cmd/govulncheck@latest ./...