Add a batch buy function allowing a single transaction to purchase keys for up to 5 different creators

[Chucks1093]

Summary

Buying keys from multiple creators requires a separate transaction per creator. A batch_buy function accepting a vec of (key_id, quantity) pairs and processing all purchases atomically would reduce the number of transactions users need to sign.

Scope

• Add a batch_buy(orders: Vec<(BytesN<32>, u32)>) function
• Validate that the vec contains between 1 and 5 entries
• Process each buy using the existing bonding curve logic in sequence
• If any single buy fails (e.g. circuit breaker, lockup), panic the entire transaction
• Emit a batch_buy_completed event listing all (key_id, quantity, price_paid) tuples

Acceptance Criteria

• batch_buy with 5 valid orders processes all successfully
• More than 5 orders panics with BatchSizeExceeded
• Failure in any single order rolls back the entire batch
• batch_buy_completed event lists all processed orders
• Total XLM deducted matches the sum of all individual order costs

ETA: 24 hours

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Coordinate on Telegram

[Davichi-1]

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Hello maintainer, i would like to work on this issue, kindly assign.

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[Stranger-11]

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Hello, I’ve carefully gone through the requirements and I’m confident I can deliver a clean implementation that aligns with the acceptance criteria. Please assign this issue to me.

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[harystyleseze]

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Hi, i would like to resolve this

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[oscar24357]

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Hello boss, good morning to you, can you please assign this issue to me

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[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox as part of the Third Campaign campaign!

@harystyleseze's PR #795 was approved and merged by @Chucks1093.

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👏 Great work, @harystyleseze! Keep contributing to accesslayerorg.

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