feat: allow processor to be unlock destination

[mpetrun5]

Description

Related Issue Or Context

Closes: #181

How Has This Been Tested? Testing details.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation

Checklist:

• I have commented my code, particularly in hard-to-understand areas.
• I have ensured that all acceptance criteria (or expected behavior) from issue are met
• I have updated the documentation locally and in docs.
• I have added tests to cover my changes.
• I have ensured that all the checks are passing and green, I've signed the CLA bot

[github-actions]

Go Test coverage is 36.7 %\ ✨ ✨ ✨

[Copilot]

Pull request overview

This PR extends the LiFi unlock-signing flow so the EIP-712 destination (repayment destination) can be routed either to the standard repayer or to a per-token “processor” address, enabling repayments to processors when the input token differs from the borrow token (Issue #181).

Changes:

• Add borrowToken to unlock requests and return the computed repaymentAddress in the API response.
• Update LifiUnlockHandler to fetch the order, resolve the input token symbol, and select either the repayer or a configured processor as the unlock destination.
• Add EVM config wiring for per-chain repayment processors and expand tests/mocks accordingly.

Reviewed changes

Copilot reviewed 10 out of 12 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
Makefile	Adds mock generation for the new unlock handler interfaces.
go.mod	Promotes github.com/lmittmann/w3 to a direct dependency; bumps solver-config version.
go.sum	Updates sums for module version changes.
chains/evm/message/unlock.go	Adds order/token-based destination selection and plumbs repayment destination through the handler.
chains/evm/message/unlock_test.go	Adds tests for repayer vs processor destination selection.
chains/evm/message/mock/unlock.go	Adds generated GoMock mocks for the new interfaces (LifiAPI, TokenResolver).
chains/evm/message/message.go	Extends LifiUnlockData with BorrowToken and a repayment destination channel.
chains/evm/config.go	Reads per-chain repayment processors from solver-config and normalizes symbols.
chains/evm/config_test.go	Updates config tests to include/verify processors mapping.
app/app.go	Wires in token resolver and constructs the unlock handler with repayer + processors + LiFi API.
api/handlers/unlock.go	Accepts borrowToken and returns repaymentAddress in the unlock response.
api/handlers/unlock_test.go	Updates expected response to include repaymentAddress.

Files not reviewed (1)

• chains/evm/message/mock/unlock.go: Language not supported

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