Frontend: campaign-form needs real contract submission flow

[alexanderkoh]

Description

The campaign creation form (components/campaign/campaign-form.tsx) has the pool selector wired to the real TinyAMM pool and rates fetched from on-chain, but the parent page (app/campaign/new/page.tsx) submit handler needs verification.

What's done

• Pool dropdown shows real TinyAMM pool from CONTRACTS.tinyamm
• FLASH rate calculated from on-chain reserves via readContract
• buildCreateCampaign() helper exists in lib/soroban.ts

What needs testing/fixing

• Verify the submit handler in app/campaign/new/page.tsx correctly maps form state to buildCreateCampaign params
• Duration is in hours in the form but needs to be converted to ledgers (1 hour ≈ 720 ledgers)
• targetTVL is in USD in the form but contract expects LP tokens (i128)
• contributionAmount needs to be converted to stroops (multiply by 1e7)
• Test full flow: fill form → submit → wallet signs → campaign appears in explore
• Error handling: show user-friendly errors for insufficient USDC, slippage, etc.