[Airdrop P5] Claim UI + burn

[realproject7]

Parent: #877
Depends on: #886, #887, #893

Scope

Update /airdrop page to show final campaign results and allow users to claim their PLOT.

Built and tested during Phase 0 test run (#892), reused at actual campaign end.

Campaign End State

When CAMPAIGN_END has passed, the /airdrop page transitions to show:

Final Results

• Campaign complete badge
• Final TWAP mcap + milestone achieved (or "No milestone reached")
• Pool distribution: X PLOT distributed, Y PLOT burned
• Burn tx link

Claim Section (replaces points panel)

• If user is eligible:
  • Show allocated amount: "You earned X PLOT"
  • [Claim PLOT] button → calls MerkleClaim.claim(amount, proof)
  • Proof fetched from API: GET /api/airdrop/proof?address=0x...
  • After claim: show "Claimed" + tx link
• If already claimed: show "Claimed" status + tx link
• If not eligible: "You did not earn any PLOT in this campaign"

API Addition

GET /api/airdrop/proof?address=0x...

Returns Merkle proof for the user's claim:

{
  "amount": "1150000000000000000000",
  "proof": ["0x...", "0x...", ...],
  "claimed": false
}

Files

• Update: src/app/airdrop/page.tsx (campaign end state)
• src/components/airdrop/ClaimPanel.tsx
• src/app/api/airdrop/proof/route.ts

Acceptance Criteria

• Page shows final results after campaign end
• Displays milestone achieved + distribution/burn amounts
• Burn tx link visible
• Eligible users can claim via MerkleClaim contract
• Claim button calls contract with correct amount + proof
• Claimed status shown after successful claim with tx link
• Non-eligible users see appropriate message
• Already-claimed users see claimed status