Dungeon v12: Cosmos SDK 0.55, IBC 11 and post-quantum support

Original Proposal Text

Upgrade dungeon-1 to v12.0.0 at height 21795500, estimated Tuesday October 13, 2026 at 16:00 UTC using the recent block-time sample (actual time may vary). The release upgrades Cosmos SDK to 0.55.0, CometBFT to 0.40.0, IBC to 11.2.0, wasmd to a local 0.70.4 compatibility port and patched WasmVM to 3.0.8. Existing Dungeon tokenfactory, Hyperlane, globalfee, groups and historical state are retained. It adds ML-DSA account and validator key-rotation support. This software upgrade preserves the Ed25519-only consensus allowlist; enabling quantum-resistant validator signing requires separate governance and coordinated signer/counterparty readiness. Existing accounts and validator keys are not automatically rotated. Tested with v10-to-v12 governance halt/resume and quantum activation on both databases, Docker Wasm/IBC/tokenfactory tests, a verified mainnet snapshot migration and 261 unchanged smart queries across 210 live contracts. The candidate also guards against duplicate database closure during SDK/Comet shutdown. Source: 8b1d988ec404b8e23df0e2ba27f150469991b2d6. Linux amd64 binary SHA256: 0c86a68d66fd4dadab945a31d163c31f4c4df7bcdf5a1f86de5618e1a31a1120. Operators must install the exact release, back up pre-upgrade state and coordinate the upgrade. Local compatibility ports and operator readiness remain subject to review. More details: https://github.com/Crypto-Dungeon/dungeonchain/pull/29