[HARD][PERIOD CLOSE] Add accounting periods, close locks, and reversal-only financial corrections

[Obiajulu-gif]

Problem

Financial records remain mutable across reporting periods. Backdated edits after statements, investor payouts, or reconciliations can make previously issued reports impossible to reproduce.

Scope

• Introduce open, soft-closed, hard-closed, and reopened accounting-period states.
• Assign every ledger entry, settlement, repayment, payout, fee, and adjustment to a period using an explicit timezone policy.
• Reject inserts or mutations into hard-closed periods.
• Correct mistakes through linked reversing and replacement entries, never destructive edits.
• Require maker-checker approval and a reason/evidence hash to reopen a period.
• Snapshot trial balance, subledger totals, reconciliation status, and report hashes at close.
• Add close-readiness checks for unmatched Paystack events, pending Stellar finality, failed jobs, and unbalanced journals.

Acceptance criteria

• Reports for a closed period are byte-for-byte reproducible.
• Closed entries cannot be edited or deleted through any API or background job.
• Reopen and correction history is complete and attributable.
• Late-arriving external events follow a documented next-period adjustment policy.
• Period close fails when financial invariants or reconciliation gates fail.

Required tests

Timezone boundaries, late events, reversal chains, concurrent close/post attempts, reopen approval, failed close recovery, and report-hash reproduction.

Non-goals

Do not implement tax rules; provide reliable accounting-period primitives.

[ebubeb683-ship-it]

Hello boss, Please assign this issue to me. i checked it out and im confident i will solve it
my eta is 4 hours

[jotel-dev]

I would like to work on this