Fix Solana transaction logic and SOL formatting

[fishingpi]

This PR fixes the following issues:

1. Corrects the transaction logic in src/lib/solana.ts to account for the reverse chronological order of signatures returned by getSignaturesForAddress.
2. Standardizes SOL amount formatting using formatUnitsString in src/lib/solana.ts.
3. Adds safety checks for log.topics in src/lib/base.ts to prevent potential runtime crashes.

[vercel]

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