feat: adjustable fee rate mode

[frolvanya]

No description provided.

[Copilot]

Pull request overview

Adds an “adjustable fee rate” mode for UTXO withdrawals so callers (and the CLI) can optionally auto-lower the effective fee rate to fit an on-chain max_gas_fee constraint, instead of always failing when the estimated gas fee exceeds that cap.

Changes:

• Introduces FeeRate (Strict vs CapToMaxGasFee) in omni-connector and wires it into BTC transfer submission paths.
• Adds utxo_utils::max_fee_rate_for_gas_fee() (an inverse helper for BTC gas fee estimation).
• Exposes the behavior via bridge-cli with a new --fee-rate-mode {exact,adjustable} flag.

Reviewed changes

Copilot reviewed 6 out of 7 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
Cargo.lock	Bumps crate versions to reflect published changes.
bridge-sdk/utxo-utils/src/lib.rs	Refactors BTC tx size calc + adds inverse helper for deriving a max fee rate from a gas-fee cap.
bridge-sdk/utxo-utils/Cargo.toml	Bumps utxo-utils version.
bridge-sdk/connectors/omni-connector/src/omni_connector.rs	Adds FeeRate strategy and implements “cap to max_gas_fee” logic for BTC submission.
bridge-sdk/connectors/omni-connector/Cargo.toml	Bumps omni-connector version and changes edition to 2024.
bridge-cli/src/omni_connector_command.rs	Adds CLI FeeRateMode and plumbs it into connector calls.
bridge-cli/Cargo.toml	Bumps bridge-cli version.

Comments suppressed due to low confidence (1)

bridge-sdk/connectors/omni-connector/src/omni_connector.rs:3621

• CapToMaxGasFee may not achieve its goal when max_gas_fee < 141 (the constant overhead): max_fee_rate_for_gas_fee will compute new_rate = 0, but get_gas_fee still returns 141, so the adjustable path can never satisfy max_gas_fee and near_submit_btc_transfer will still fail with InsufficientUTXOGasFee. Consider explicitly detecting this case (or, more generally, re-checking new_gas_fee <= max) and returning a clearer error early, so callers don’t expect the transaction to be broadcastable.

        if allow_cap
            && let Some(max) = max_gas_fee
            && gas_fee > u128::from(max)
            && let Some(new_rate) =
                utxo_utils::max_fee_rate_for_gas_fee(chain, num_inputs, num_outputs, max)

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.