* chore: remove dead git tuning knobs and duplicate release/frontend files
- GitTuningConfig: drop upload_concurrency, restore_concurrency,
ref_cas_max_retry, and ref_cas_backoff_ms, which were parsed but never read
anywhere (verified no source readers). Keep commit_index_enabled and
blob_exists_precheck_enabled, the two knobs that actually take effect.
- Design doc: mark the removed knobs as roadmap items to be added back when
the behavior lands, and correct stale 'not implemented' claims
(validate_account_id is enforced at the Git service entry; blob reads are
limited via show_with_limit).
- Remove .github/workflows/release-vikingbot-first.yml: a historical one-off
PyPI release workflow whose bot/ package lacks build metadata.
- web-studio: delete pnpm-lock.yaml and the pnpm-only package.json block;
the Makefile and CI already use npm + package-lock.json as the single
install chain. Net -9,695 lines.
* docs: align cleanup notes with current behavior
---------
Co-authored-by: qin-ctx <qinhaojie.exe@bytedance.com>
