feat: add query_price helper and protocol fee boundary tests (#572)

[edehvictor]

Closes #572

Summary

Adds a read-only \query_price(env: Env, creator: Address, supply: u64)\ helper function to \CreatorKeysContract\ along with comprehensive unit tests for \query_price\ and protocol fee calculation at boundary supply values.

Changes

• **\creator-keys/src/lib.rs**: Added \query_price(env: Env, creator: Address, supply: u64) -> Result<i128, ContractError>\ to \CreatorKeysContract. Computes the bonding curve price for a given supply step without requiring authorization or modifying storage state.
• **\creator-keys/src/test_issues.rs**: Added unit tests:
  • \ est_query_price_at_boundary_supplies: Asserts \query_price\ output matches buy-path formula across supply steps 0, 1, and 50 for Flat, Linear, and Quadratic presets.
  • \ est_protocol_fee_calculation_at_boundary_supplies: Asserts protocol fee calculation at boundary supply values 0, 1, and 1000 against configured \protocol_bps.
  • \ est_protocol_fee_floors_on_non_whole_stroops: Asserts protocol fee calculation floors (rounds down) on non-whole stroop amounts.

Testing

• Verified read-only contract function signature and unit tests added for Issue Add read-only price query helper and unit tests for protocol fee calculation at boundary supply values #572.

[Chucks1093]

Fix ci

[Chucks1093]

I see what you have done here, the price check tool and fee edge case tests make it easy to verify the math holds at boundary values. Good work.