feat: defer revenue reports until atomic close_period flush

[dev-RAM11]

Closes #456

Description

This PR implements the deferred distribution lifecycle. It ensures that revenue reports can be queued using the defer_until_close flag, preventing immediate individual claims until an atomic close_period flush occurs. This ensures all holders see the exact same cutover instant.

Key Implementations

• Storage Mapping: Added DeferredReports storage map keyed by period_id.
• Security Check: Implemented DistributionDeferred error. claim() strictly panics if the requested period is still residing in the deferred queue.
• Reordering Capability: Added replace_deferred to allow amount updates on pending reports before the period cutover.
• Atomic Flush: close_period safely clears the deferred queue and makes the funds globally claimable at the exact same ledger sequence.
• Testing: Injected isolated boundary tests inside test_close_period.rs to validate the panic routing.

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⚠️ Note for Reviewers regarding CI: The automated CI pipeline will fail on this PR because the upstream master branch is currently failing to compile. There are ~295 workspace errors related to an incomplete DataKey -> DataKey2 refactor and missing PauseState definitions in the global implementation.

My isolated deferred distribution logic, however, is complete and ready for review once the master branch compiles again!