Arbitrum gas price spikes causing outbound transactions failures #192
Description
Problem
Outbound transactions on Arbitrum frequently get rejected during broadcasting due to gas price spikes. The gas price fetched by the chain meta oracle becomes stale by the time the transaction is actually broadcast.
Why Arbitrum
Arbitrum has a two-component fee model - L2 execution fee + L1 data posting fee. The sequencer reprices aggressively with ~250ms block times (vs 12s on Ethereum, 3s on BSC), and the L1 data component fluctuates with Ethereum mainnet gas prices. This makes the gas price inherently more volatile than on L1 chains.
Solution
Added a per-chain gas_price_markup_percent config that applies a percentage buffer on top of the fetched gas price before reporting it. Currently set to 10 (10%) for Arbitrum, 0 for all other chains.
Configurable per-chain so it can be tuned as needed.