feat: implement responsive MarketCard layout

[VictorEzenma]

Summary

Closes #671

Type of change

• feat — new feature
• fix — bug fix
• refactor — code change that neither fixes a bug nor adds a feature
• perf — performance improvement
• test — adding or updating tests
• docs — documentation only
• ci — CI / workflow changes
• chore — dependency bump or tooling update

Scope

• Contract (contracts/)
• Frontend / Web (web/)
• Docs (docs/)
• CI / Ops (.github/)

---

Contract changes (complete if scope includes contracts/)

• New or changed public functions — ABI impact documented below
• Storage layout changed — migration path described below
• Tests added or updated for every changed function

ABI / storage notes:

---

Frontend changes (complete if scope includes web/)

• UI tested in a browser on the happy path
• Responsive layout verified (mobile / desktop)
• No new console.error or TypeScript errors introduced

---

Testing

• Existing tests still pass (cargo test / npm run test)
• New tests added for new behaviour
• Manual steps to verify this change:

Docs impact

• README or docs updated (or N/A)
• Changelog entry added (or N/A)

Additional notes

[drips-wave]

@VictorEzenma Great news! 🎉 Based on an automated assessment of this PR, the linked Wave issue(s) no longer count against your application limits.

You can now already apply to more issues while waiting for a review of this PR. Keep up the great work! 🚀

Learn more about application limits