feat: read swap cost priceData from bridge-api response

[micaelae]

Explanation

This change reads the cost metadata provided by the backend and uses it to sort quotes:

{
  quote: {
    priceData: {
      cost: {
        usd: "1.53252"
      }
    }
  }
}

Other changes

• priceImpact is no longer used as the quote cost
• sort quotes by cost if it exists, use priceImpact as a fallback

References

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've communicated my changes to consumers by updating changelogs for packages I've changed
• I've introduced breaking changes in this PR and have prepared draft pull requests for clients and consumer packages to resolve them

---

Note

Medium Risk
Changes recommended-quote selection and displayed cost metadata in swap/bridge flows; incorrect backend cost data could surface the wrong quote, but scope is limited to quote presentation and sorting.

Overview
Bridge quotes now consume priceData.cost from the bridge API instead of treating priceImpact as cost. Quote validation, fiat conversion (toCurrencyValues), and V1/V2 metadata mappers were updated so cost is a distinct field on priceData and on merged quote metadata.

Default quote ordering prefers ascending priceData.cost.valueInCurrency when every quote has it; otherwise it keeps the existing fallbacks (priceImpact.amount, then priceImpact.valueInCurrency, then destination amount). That changes which quote is recommended when the API sends cost.

Tests and snapshots were extended for the new sort priority, Phase 1.5 fallbacks, and related selector edge cases.

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