fix(tbtcpg): use RedemptionParameters struct return, not old 8-tuple

[piotr-roslaniec]

Problem

main currently fails to build. client-scan, client-vet, client-lint, and client-build-test-publish all fail on the latest main commit (fac4b79b1):

pkg/tbtcpg/redemptions.go:225:50: assignment mismatch: 8 variables but rt.chain.GetRedemptionParameters returns 2 values

Root cause

Two same-day (2026-07-23) divergent commits landed without either being an ancestor of the other:

• c4cc0addd refactored GetRedemptionParameters() from an 8-value positional return to a single tbtc.RedemptionParameters struct + error.
• ad89b38d9/6a7060800 (separate branch, same day) added a new call site in redemptions.go:225 still using the old 8-value destructuring.

The merge that combined both branches didn't catch the mismatch.

Fix

Use the already-fetched redemptionParameters struct (same pattern as the call site at line 155) instead of the stale positional destructuring. txMaxFee/txMaxTotalFee become redemptionParameters.TxMaxFee/redemptionParameters.TxMaxTotalFee.

Verification

• go vet ./pkg/tbtcpg/... clean.
• go build ./pkg/tbtcpg/... succeeds.
• go test ./pkg/tbtcpg/... -run TestEstimate — all pass (TestEstimateRedemptionFee, TestEstimateDepositsSweepFee_MinimumFloorAndBuffer, TestEstimateMovedFundsSweepFee, TestEstimateMovingFundsFee).

Summary by CodeRabbit

• Bug Fixes
  • Improved redemption fee estimation and fee-share warnings by using the correct transaction fee limits.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 19e87557-cf45-4409-950e-db10123fb693

📥 Commits

Reviewing files that changed from the base of the PR and between fac4b79 and b13ccea.

📒 Files selected for processing (1)

• pkg/tbtcpg/redemptions.go

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📝 Walkthrough

Walkthrough

ProposeRedemption now uses named fields from structured redemption parameters for fee estimation and per-request fee-share warnings.

Changes

Redemption fee parameter usage

Layer / File(s)	Summary
Fee parameter consumption pkg/tbtcpg/redemptions.go	ProposeRedemption uses TxMaxTotalFee for fee estimation and TxMaxFee for per-request fee-share warnings.

Estimated code review effort: 1 (Trivial) | ~5 minutes

Possibly related PRs

• threshold-network/keep-core#4188: Introduces the structured RedemptionParameters return value consumed by this change.
• threshold-network/keep-core#4192: Modifies redemption fee handling in the same function.
• threshold-network/keep-core#4194: Updates redemption fee-cap handling in the same function.

Suggested reviewers: lrsaturnino

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly describes the main change: updating redemption parameter handling from an outdated tuple to the RedemptionParameters struct.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/redemption-parameters-struct-call

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