Build recurring payroll schedule state machine

[edehvictor]

Summary

Add a schedule state machine for recurring payroll periods, including draft, locked, executable, missed, and finalized states.

Why This Matters

Recurring payroll needs predictable state transitions so dashboard and SDK clients do not invent conflicting timing rules.

Suggested Files

• contracts/src/schedule.rs
• contracts/src/payroll.rs
• contracts/src/policy.rs
• contracts/tests/recurring_schedule.rs

Tasks

• Define schedule states and allowed transitions.
• Move payroll periods through states based on policy and ledger time.
• Reject invalid manual transitions.
• Add tests for normal and missed payroll timelines.

Acceptance Criteria

• Schedules progress through valid states only.
• Missed payroll windows are represented explicitly.
• Invalid transitions return stable errors.
• Tests cover time-based and manual transitions.

Coordination

Join the Telegram channel for proper coordination: https://t.me/zkpayroll

[shobhamerabacha-star]

Hey team,

I would love to take this on. My planned approach:

• Implement Build recurring payroll schedule state machine with explicit require_auth checks, clean storage layouts, and robust Soroban contract logic.
• Add comprehensive unit tests verifying both happy-path invocations and unauthorized revert scenarios.

Happy to pick this up today—please assign to me!