fix: cumulative fund claims — deposits accumulate until claimed

Instead of expiring old claims, new deposits add to the existing
pending claim's fiat_amount and extend the expiry. The claim email
shows the updated total.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/encryptid/db.ts

@@ -1271,6 +1271,18 @@ export async function acceptFundClaim(token: string, userId: string): Promise<St
   return rowToFundClaim(rows[0]);
 }
 
+export async function accumulateFundClaim(claimId: string, additionalAmount: string, expiresAt: number): Promise<StoredFundClaim | null> {
+  const rows = await sql`
+    UPDATE fund_claims
+    SET fiat_amount = (COALESCE(fiat_amount::numeric, 0) + ${additionalAmount}::numeric)::text,
+        expires_at = ${new Date(expiresAt)}
+    WHERE id = ${claimId} AND status IN ('pending', 'resent')
+    RETURNING *
+  `;
+  if (rows.length === 0) return null;
+  return rowToFundClaim(rows[0]);
+}
+
 export async function expireFundClaim(claimId: string): Promise<void> {
   await sql`UPDATE fund_claims SET status = 'expired', email = NULL WHERE id = ${claimId} AND status IN ('pending', 'resent')`;
 }

src/encryptid/server.ts

@@ -77,7 +77,7 @@ import {
   getFundClaimByToken,
   getFundClaimsByEmailHash,
   acceptFundClaim,
-  expireFundClaim,
+  accumulateFundClaim,
   cleanExpiredFundClaims,
   sql,
 } from './db.js';
@@ -2926,17 +2926,30 @@ app.post('/api/internal/fund-claims', async (c) => {
     return c.json({ error: 'email and walletAddress are required' }, 400);
   }
 
-  const id = crypto.randomUUID();
-  const token = generateToken();
   const emailHashed = await hashEmail(email);
   const expiresAt = Date.now() + 7 * 24 * 60 * 60 * 1000; // 7 days
 
-  // Expire any existing pending claims for this email (one active claim per user)
+  // Check for existing pending claim — accumulate deposits
   const existingClaims = await getFundClaimsByEmailHash(emailHashed);
-  for (const ec of existingClaims) {
+  if (existingClaims.length > 0 && fiatAmount) {
-    await expireFundClaim(ec.id);
+    const existing = existingClaims[0];
+    const updated = await accumulateFundClaim(existing.id, fiatAmount, expiresAt);
+
+    let sent = false;
+    try {
+      const totalAmount = updated?.fiatAmount || fiatAmount;
+      sent = await sendClaimEmail(email, existing.token, totalAmount, fiatCurrency || 'USD');
+    } catch (err) {
+      console.error('EncryptID: Failed to send claim email:', err);
+    }
+
+    return c.json({ claimId: existing.id, accumulated: true, sent });
   }
 
+  // No existing claim — create new
+  const id = crypto.randomUUID();
+  const token = generateToken();
+
   const claim = await createFundClaim({
     id,
     token,