[flashloan] AaveFlashLoan PoolDataProvider address hardcoded — should be in config/default.toml

[obchain]

Refs #39

File: crates/charon-flashloan/src/aave.rs — hardcoded PoolDataProvider constant

Problem

All protocol addresses in this project live in config/default.toml and are loaded at runtime via Config. This ensures addresses can be updated without a recompile, and the config file serves as the single source of truth for all on-chain addresses. The BSC Aave V3 PoolDataProvider (0x41393e5e337606dc3821075Af65AeE84D7688CBD) is hardcoded as a constant inside the adapter, breaking this invariant.

config/default.toml already has [flashloan.aave_v3_bsc] with a pool field. A data_provider field belongs alongside it.

Fix

1. Add to FlashLoanConfig in crates/charon-core/src/config.rs:
   pub data_provider: Address,

2. Add to config/default.toml under [flashloan.aave_v3_bsc]:
   data_provider = "0x41393e5e337606dc3821075Af65AeE84D7688CBD"

3. Pass data_provider into AaveFlashLoan::connect() from the caller that reads Config. Remove the hardcoded constant.

[obchain]

Resolved in b9092e1 on feat/14-flashloan-router. FlashLoanConfig gains an optional data_provider: Option

(Balancer and Uniswap won't need one). config/default.toml pins the canonical Aave V3 BSC PoolDataProvider 0x41393e5e337606dc3821075Af65AeE84D7688CBD under [flashloan.aave_v3_bsc]. AaveFlashLoan::connect now takes the data_provider address as an argument; the old AAVE_V3_BSC_DATA_PROVIDER constant is gone. Multi-chain expansion is now a config change, not a code change.