Support ACP-236 auto-renewed staking P-Chain transaction types

[owenwahlgren]

Summary

Add support for the three new P-Chain transaction types introduced by ACP-236: Auto-Renewed Staking. This ACP replaces the current fixed-duration staking model with cycle-based auto-renewing validators.

New Transaction Types

1. AddAutoRenewedValidatorTx

Creates an auto-renewing validator position.

Parameters:

• ValidatorNodeID — Node ID
• Signer — BLS key
• StakeOuts — Return destination for staked tokens
• ValidatorRewardsOwner / DelegatorRewardsOwner — Reward distribution
• Owner — Controls config updates
• DelegationShares — Delegation fee (×10,000)
• Wght — Validator weight
• AutoCompoundRewardShares — Percentage of rewards to restake (in millionths)
• Period — Cycle duration in seconds (bounded by MinStakeDuration/MaxStakeDuration)

2. SetAutoRenewedValidatorConfigTx

Modifies an existing auto-renewed validator's config. Changes take effect at cycle end.

Parameters:

• TxID — Original AddAutoRenewedValidatorTx ID
• Auth — Owner authorization proof
• AutoCompoundRewardShares — Updated restake percentage
• Period — Next cycle duration (set to 0 for graceful exit)

3. RewardAutoRenewedValidatorTx

Handles end-of-cycle reward distribution and validator continuation/exit.

Parameters:

• TxID — Original validator creation tx ID
• Timestamp — Cycle end time

Key Behavioral Changes

• Cycle-based staking: Uptime measured per-cycle with resets at boundaries
• Auto-compounding: Configurable portion of rewards automatically restaked
• Graceful exit: Set Period to 0 to stop at cycle end (no immediate unstake)
• Delegator restrictions: Delegations cannot span multiple cycles
• Stake overflow: Excess beyond MaxValidatorStake withdrawn to rewards owners

CLI Commands to Add

platform validator add-auto-renewed   # AddAutoRenewedValidatorTx
platform validator set-auto-config     # SetAutoRenewedValidatorConfigTx
platform validator reward-auto         # RewardAutoRenewedValidatorTx (if manual trigger needed)

Implementation Notes

• Requires upstream avalanchego SDK support for these tx types — track SDK readiness
• New tx builders needed in pkg/pchain/
• New cobra commands in cmd/validator.go
• AutoCompoundRewardShares is expressed in millionths (1,000,000 = 100%)
• Period of 0 in SetAutoRenewedValidatorConfigTx means "exit after current cycle"
• Unit tests + e2e tests against local network once avalanchego supports ACP-236

References

• ACP-236 Spec