Fix pool performance metrics display

[autochamchikim-pixel]

Summary

• Replaces the hard-coded 30%+ pool performance display with a derived performance value per asset.
• Keeps fee APY derived from the documented monthly fee assumptions, but centralizes the fee constants and guards non-numeric/zero balances.
• Adds USD sub-values for trader UP/L and buffer balances so the table no longer mixes raw asset units with unexplained metrics.

Root cause

The pool table had one dynamic yield column and one static placeholder: 30%+ was rendered for every asset regardless of pool balance or global trader UP/L. That made the displayed pool performance nonsensical and unable to react to the actual pool state shown in the adjacent columns.

Reproduction / failing case

Open the Pool page with any non-zero pool balance and a non-zero global UP/L. Before this change, the pool performance column still displayed 30%+ for both ETH and USDC, so the value did not change when the pool balance or trader UP/L changed.

Changed files / scope

• src/components/pool/Pools.svelte only.
• No route, contract, wallet, or store changes.

Implementation notes

• MONTHLY_FEES keeps the existing fee assumptions: ~95 ETH/month and ~100,000 USDC/month.
• feeAPY is recomputed for each supported pool asset and falls back to 0 when data is missing.
• Pool performance is displayed as feeAPY - traderUPL / poolBalance * 100, because positive trader UP/L is owed by the pool and reduces pool-side performance.
• Missing/zero balances render - rather than NaN%/Infinity%.

Validation

• NODE_OPTIONS=--max-old-space-size=2048 npm run build ✅
  • Build completed and created build/bundle.dd73831.js.
  • Existing Svelte/Rollup warnings are still present and are unrelated to this one-file pool table change.

Edge cases covered

• Zero or missing pool balance.
• Missing/non-numeric fee, UP/L, or balance values.
• Assets without a monthly fee constant.
• Positive and negative trader UP/L values.

Risk / compatibility

Low risk: this is a display-only change inside the Pool table. It preserves the existing monthly fee assumptions and does not modify state, transactions, stores, or contract calls.

Acceptance checklist

• Pool performance is no longer a hard-coded placeholder.
• Metrics are derived from the same per-asset pool state shown in the table.
• Invalid arithmetic is guarded so users do not see NaN% or Infinity%.
• Minimal one-file change with a successful targeted production build.

Closes #6