Restore liquidity-aware weighting for centralized exchange prices

[micahkendall]

Motivation

• A recent change emitted reliability: Decimal::ONE for multiple CEX feeds, which removed liquidity/volume weighting used by the aggregator and allowed thin or compromised exchanges to skew the aggregated price.
• The aggregator computes weighted averages using reliability, so feeds must report a liquidity-derived weight rather than a constant to preserve robustness.

Description

• Restored volume-derived reliability for Binance by parsing v (volume_base) and setting PriceInfo.reliability to that value in src/sources/binance.rs.
• Restored Bybit to use volume_24h (with a cached last-volume fallback) as reliability in src/sources/bybit.rs.
• Restored Coinbase, Crypto.com, Kucoin, and Maestro to forward their reported volume fields as reliability in src/sources/coinbase.rs, src/sources/crypto_com.rs, src/sources/kucoin.rs, and src/sources/maestro.rs respectively.
• Performed small cleanup (removed unnecessary imports) and formatted the code with cargo fmt.

Testing

• Ran cargo fmt --all which completed successfully.
• Ran cargo test --all --quiet and all automated tests passed (94 tests passed, 0 failed).

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Codex Task