feat: store dao member count of each epoch

[kyubinokitsune-ace]

No description provided.

[kyubinokitsune-ace]

I've created a comprehensive description of the smart contract implementation. Here's a summary:

Smart Contract Changes Summary

What was added:

• New field numberOfDaoMembers to QuRaffleInfo struct (4 bytes per epoch)
• Store state.numberOfRegisters during END_EPOCH
• Return numberOfDaoMembers in getEndedQuRaffle function

Why it's needed:

• DAO members (registered users) receive 5% dividends from ALL raffles
• DAO member count changes over time (users register/logout)
• QRaffle need historical DAO member counts to calculate per-member dividends
• Previously required manual tracking or transaction replay

Key distinction:

• numberOfMembers = raffle participants (who entered that specific raffle)
• numberOfDaoMembers = DAO registered users (who receive dividends from all raffles)

Impact:

• Memory: ~256 KB additional storage (4 bytes × 65536 epochs)
• Performance: No impact, just storing one additional uint32 per epoch
• Backward compatible: Legacy epochs will have numberOfDaoMembers = 0

The implementation is minimal, efficient, and solves the qraffle's problem of needing to manually track DAO member counts for historical dividend calculations.