WIRE-301: Retire legacy staking attestations

[huangminghuang]

Summary

• Reserve and remove the retired STAKE/UNSTAKE protobuf slots and pretoken stake payload.
• Tombstone legacy READY rows before envelope construction so historical queue entries cannot block or reach an outpost decoder.
• Preserve opaque Solidity decoding for reserved raw values solely so in-flight historical envelopes can reach an explicit outpost blackhole.
• Update contract reflection, ABIs, diagrams, tests, and the tracked Release sysio.msgch.wasm.

Validation

• Focused msgch/dispatch contract suites: 64/64 passed.
• Solidity generator: 83/83 tests passed; generated TypeScript, Solidity, and Solana bundles validated.
• Full Release CTest: 2,312/2,314 passed; only the two Git version-label checks fail in the dedicated worktree layout.
• git diff --check passed; tracked sysio.msgch.wasm byte-matches the Release build.

Rollout

Draft pending synchronized generated-model 1.0.43 publication, downstream manifest/lock updates and clean-install validation, companion PRs, GitHub CI, and the shared Release E2E run. Deployment must keep the outpost blackhole migration ahead of selector removal and the depot tombstone deployment.