Add dependency-free BOLT11 amount decoder; drop removed nip57 helper

Newer nostr-tools removed nip57.getSatoshisAmountFromBolt11, breaking
useZaps and useCrewGoal. Add src/lib/bolt11.ts (getSatoshisFromBolt11)
that parses the sat amount straight from the invoice's human-readable
prefix — no external dependency, immune to nostr-tools API churn — and
use it in both hooks.

Co-authored-by: shakespeare.diy <assistant@shakespeare.diy>

src/hooks/useCrewGoal.ts

@@ -1,8 +1,8 @@
 import { useQuery, type UseQueryResult } from '@tanstack/react-query';
 import { useNostr } from '@nostrify/react';
-import { nip57 } from 'nostr-tools';
 import type { NostrEvent } from '@nostrify/nostrify';
 import { ZAP_GOAL_KIND } from '@/lib/types';
+import { getSatoshisFromBolt11 } from '@/lib/bolt11';
 
 export interface CrewGoal {
   id: string;
@@ -43,7 +43,7 @@ function tallyZaps(receipts: NostrEvent[], closedAt?: number): { sats: number; c
     const bolt11 = z.tags.find(([n]) => n === 'bolt11')?.[1];
     if (bolt11) {
       try {
-        sats += nip57.getSatoshisAmountFromBolt11(bolt11);
+        sats += getSatoshisFromBolt11(bolt11);
         count++;
         continue;
       } catch {

src/hooks/useZaps.ts

@@ -7,6 +7,7 @@ import { useNWC } from '@/hooks/useNWCContext';
 import type { NWCConnection } from '@/hooks/useNWC';
 import { nip57 } from 'nostr-tools';
 import type { Event } from 'nostr-tools';
+import { getSatoshisFromBolt11 } from '@/lib/bolt11';
 import type { WebLNProvider } from '@webbtc/webln-types';
 import { useQuery, useQueryClient } from '@tanstack/react-query';
 import { useNostr } from '@nostrify/react';
@@ -99,7 +100,7 @@ export function useZaps(
       const bolt11Tag = zap.tags.find(([name]) => name === 'bolt11')?.[1];
       if (bolt11Tag) {
         try {
-          const invoiceSats = nip57.getSatoshisAmountFromBolt11(bolt11Tag);
+          const invoiceSats = getSatoshisFromBolt11(bolt11Tag);
           sats += invoiceSats;
           return;
         } catch (error) {

src/lib/bolt11.ts

@@ -0,0 +1,67 @@
+/**
+ * Minimal, dependency-free BOLT11 Lightning invoice amount decoder.
+ *
+ * WHY THIS EXISTS
+ * ---------------
+ * nostr-tools removed `nip57.getSatoshisAmountFromBolt11` in a newer minor, so
+ * we decode the amount ourselves. The amount is encoded in the invoice's
+ * human-readable prefix (HRP), NOT the bech32 data — so we don't need a full
+ * bech32 decode, just to parse the leading `ln<network><amount><multiplier>`.
+ *
+ * BOLT11 amount format (from the spec):
+ *   - HRP looks like:  lnbc<amount?><multiplier?>1<data...>
+ *   - <amount> is an integer; <multiplier> is one of:
+ *       m (milli)  = 0.001 BTC
+ *       u (micro)  = 0.000001 BTC
+ *       n (nano)   = 0.000000001 BTC
+ *       p (pico)   = 0.000000000001 BTC
+ *   - No amount at all  → a "donation" invoice (0 / unspecified).
+ *
+ * 1 BTC = 100_000_000 sats.
+ */
+
+const MULTIPLIERS: Record<string, number> = {
+  m: 0.001,
+  u: 0.000001,
+  n: 0.000000001,
+  p: 0.000000000001,
+};
+
+const SATS_PER_BTC = 100_000_000;
+
+/**
+ * Decode the amount (in whole satoshis) from a BOLT11 invoice string.
+ * Returns 0 for amountless invoices. Throws on a clearly malformed prefix so
+ * callers can fall back to other amount sources (e.g. the zap `amount` tag).
+ */
+export function getSatoshisFromBolt11(invoice: string): number {
+  if (!invoice || typeof invoice !== 'string') {
+    throw new Error('Invalid BOLT11 invoice');
+  }
+
+  const lower = invoice.trim().toLowerCase();
+
+  // The HRP is everything before the bech32 separator '1' that precedes the
+  // data part. BOLT11 HRPs start with "ln". Grab from the start up to (but not
+  // including) the final separator between HRP and data. In practice the amount
+  // block sits right after the network prefix (lnbc / lntb / lntbs / lnbcrt).
+  const match = lower.match(/^ln(?:bc|tb|tbs|bcrt|sb)(\d+)?([munp])?1/);
+  if (!match) {
+    throw new Error('Not a recognizable BOLT11 invoice');
+  }
+
+  const amountStr = match[1];
+  const multiplier = match[2];
+
+  // No amount encoded → amountless invoice.
+  if (!amountStr) return 0;
+
+  const amount = parseInt(amountStr, 10);
+  if (Number.isNaN(amount)) {
+    throw new Error('Invalid amount in BOLT11 invoice');
+  }
+
+  // btc value = amount * multiplier (multiplier absent means whole BTC units).
+  const btc = multiplier ? amount * MULTIPLIERS[multiplier] : amount;
+  return Math.round(btc * SATS_PER_BTC);
+}