Add worst-case HF stress panel

[Sikkra]

Summary

• Adds a worst-case 99% utilization panel under the leverage preview.
• Computes stressed borrow APR, supply APR, spread, and 30-day HF movement from the live Blend rateConfig using the same fixed-point kink math as projectRates.
• Includes position supply/borrow amounts so the scenario updates with amount and leverage changes.
• Enables frontend tsc --noEmit by allowing .ts imports and removing stale wallet modal params.

Verification

• npm run build
• npx tsc --noEmit
• git diff --check
• Browser check on http://127.0.0.1:5195: accepted disclaimer, opened demo mode, verified the panel renders, updates when amount/leverage inputs change, and current-page console logs contain no warnings/errors.

Closes #41