v0.27.12 — Certified competing-tip synchronization

Shell Chain v0.27.12

Fixed

• Discover a quorum-certified competing block at an unfinalized local tip without
  waiting for a higher descendant. Keep synchronization above the finalized
  checkpoint and retain deterministic replay before changing canonical state.
• Recover missed finality evidence when a synchronized block is already stored
  locally. Reverify each stored quorum certificate before accepting a proposer
  from a historical view during fork replay.
• Keep peer networking responsive while generating a slow post-quantum
  view-change signature, including on a single-worker async runtime.

Added

• Add native unequal-weight and same-height fork acceptance covering independent
  canonical state, receipts, genuine signer evidence, orphan removal and RocksDB
  reopen. Reject malformed and wrong-block certificates without state changes.

Native archives

The attached archives include RocksDB storage and libp2p networking. Verify the selected archive with SHA256SUMS before extracting shell-node.

• Linux: x86-64 GNU/Linux, built on Ubuntu 22.04.
• macOS: Apple Silicon, deployment target macOS 13.0; runtime acceptance was performed on macOS 15.

This release does not change quorum thresholds, wire formats, database formats, chain identifiers, or network activation settings.