fix(deploy): make published scripts compatible with ethers v5/v6 and replay

[mswilkison]

Consumers replay this package's published deployment scripts after copying existing deployment records. Today that can repeat the 4.5B T transfer, call an already-used initializer, or grant a timelock role after the deployer has relinquished administration. The mainnet proxy path also depends on ethers v5-only contract and Interface APIs.

Use on-chain balances, governance and role membership to skip completed work; fund only the vending-machine shortfall and fail if the deployer cannot cover it. Reuse TokenStaking records, recover an interrupted initialization, and save mainnet proxy addresses/ABI through hardhat-deploy using the consumer's HRE. Make the mainnet governance and proxy-admin handoffs replay-safe too. The producer remains on its existing ethers v5 dependencies.

The CI producer follows .nvmrc when available (including #182's Node 22 toolchain) and otherwise retains Node 18 for the legacy lockfile. The new CI consumer matrix installs the actual prepacked tarball on ethers v5 and v6 (hardhat-ethers 3 / upgrades 2.5.1). Each lane runs both direct and mainnet-style proxy deployment on fresh local chains, then replays with distinct deployer/council accounts and asserts unchanged account nonces and deployment addresses. It also checks partial/excess funding, insufficient funds, initializer recovery, saved ABI and ownership handoffs.

Validation: locked producer build and prepack, lint, formatting checks, and all four consumer scenarios pass locally. The full Solidity suite passed in CI. The producer integrated with #182 was also built and prepacked on Node 22; all four packed consumer scenarios passed on ethers 5.8.0 and 6.17.0. Workflow formatting and actionlint pass. No live network or npm publication is involved.

Addresses #184; sibling fix: threshold-network/keep-core#4320. Publishing the package, updating keep-core pins, and removing tbtc-v2's overrides remain release follow-ups.