fix: cap stx contract call fees

[teebszet]

🔘 PR Type

What kind of change does this PR introduce?

• [x] Bugfix
• [ ] Enhancement
• [ ] Code style update (formatting, local variables)
• [ ] Refactoring (no functional changes, no API changes)
• [ ] Build related changes
• [ ] CI related changes
• [ ] Documentation content changes
• [ ] Other... Please describe:

📜 Background

stackerDAO reported really high fees when stacking via their dapp here: https://app.stackingdao.com/stack

we are taking fee estimates from the hiro endpoint https://api.hiro.so/v2/fees/transaction, but the endpoint currently responds with really high estimates (~50STX).

this PR will set the fee capped at the threshold determined from our xverse-api (currently 1STX)

depends on: https://github.com/secretkeylabs/xverse-core/pull/324

🔄 Changes

• fix: enforce a cap on the STX fee for contract function calls (stacking on stackerDAO)

Impact:

• Explain the broader impact of these changes.
• How it improves performance, fixes bugs, adds functionality, etc.

🖼 Screenshot / 📹 Video

✅ Review checklist

Please ensure the following are true before merging:

• [ ] Code Style is consistent with the project guidelines.
• [ ] Code is readable and well-commented.
• [ ] No unnecessary or debugging code has been added.
• [ ] Security considerations have been taken into account.
• [ ] The change has been manually tested and works as expected.
• [ ] Breaking changes and their impacts have been considered and documented.
• [ ] Code does not introduce new technical debt or issues.

[github-actions[bot]]

Test with build here: https://github.com/secretkeylabs/xverse-web-extension/actions/runs/7263246195