Lender: Loan actions

[ardier16]

Describe the feature

Description:
Implement lender modals for accepting offers, liquidating expired loans, and claiming payouts.

Acceptance Criteria:

• Accept Offer modal:
  • Display offer details:
    • Borrower collateral (LBTC)
    • Principal (USDT)
    • APR (%)
    • Term (blocks/days)
    • Lender principal covenant hash (display for transparency)
  • "Accept & Supply" button → Build → Sign with Jade → Broadcast
  • Transaction states: pending → success (txid link) → error (retry)
  • Modal closes on success; offer moves to "Active Loans"
• Liquidation modal (appears when loan expired, block height > expiration):
  • Display loan details:
    • Borrower collateral (LBTC)
    • Current status: "Expired" (red badge)
    • Expiration block + time ago
    • Collateral to claim (LBTC)
  • "Liquidate & Claim Collateral" button → Build → Sign with Jade → Broadcast
  • Transaction states: pending → success (txid link) → error (retry)
  • Modal closes on success
• Claim modal (appears when loan repaid or liquidated, ready to claim):
  • Display claimable amount:
    • Principal (USDT)
    • Interest earned (USDT)
    • Total to claim (USDT)
  • "Claim" button → Build → Sign with Jade → Broadcast
  • Transaction states: pending → success (txid + amount) → error (retry)
  • Modal closes on success; offer removed from active list
• Transaction builders called:
  • buildAcceptOfferTx() — lender accepts offer
  • buildLoanLiquidationTx() — liquidate collateral
  • Claim uses same logic as loanRepayment finalization (port if needed)
• All tx signing via Jade (Pretty #3)
• Manual test: All three flows work end-to-end on testnet, match Figma

Notes:

• Flows match Figma: "Accept & Supply", "Liquidate", "Claim"
• Check offer status before rendering modals (avoid invalid states)
• Show countdown timer for expiration if loan will expire soon