Adds tests/cli/webview/Taskfile.yaml with canonical build/test/vet/default
targets plus test-unit and CHROME_ADDR-gated test-integration (skipped
cleanly when no Chrome endpoint set). default deps-chains build/test/vet
per Wave 2 convention.
Co-authored-by: Codex <noreply@openai.com>
Via-codex-lane: supervised by Cerberus on Athena #106 request
Closes tasks.lthn.sh/view.php?id=290
