Fix Base ETH drips to delegated wallets

[ameya-deshmukh]

Summary

Base ETH drips used a fixed 21,000 gas limit, which is insufficient for delegated wallets. Estimate the transaction gas before signing and safely recover affected legacy requests.

Changes

• Use eth_estimateGas with 25% headroom for Base native transfers; reject estimates whose padded limit exceeds 100,000 gas.
• Keep transfer amounts and ERC20/Seismic transaction behavior unchanged.
• Recover only matching, signed legacy 21,000-gas Base ETH transfers whose receipts confirm a revert at the configured confirmation depth.
• Under the operator lease, atomically archive the old failure and requeue the original idempotency record without another value-budget reservation.
• Preserve pending transaction bytes and successful-response replay; new estimated-gas failures do not qualify for legacy recovery.

Tests

• Reproduced the original failure with a 21,220-gas RPC estimate and a signed 21,000-gas transaction; regression now signs with 26,525 gas.
• RPC-level retry eligibility and confirmation checks, signature/input matching, and gas-budget boundaries.
• Redis integration coverage for concurrent retries, restart recovery, retained failure history, stale-state rejection, and unchanged reservation limits.
• cargo fmt --all -- --check
• cargo clippy --workspace --all-targets --locked -- -D warnings
• cargo test --workspace --locked (also passed serially; an initial parallel run hit the existing lock-deadline timing assertion, and the final standard run passed)

No Linear issue linked.