Bug: TxHistory formatTimestamp doesn't handle seconds vs milliseconds — shows 1970 dates

[gboigwe]

Description

In frontend/src/components/wallet/TxHistory.tsx (lines 77-91), the formatTimestamp function accepts a timestamp: number but has no validation for the unit (milliseconds vs seconds):

const formatTimestamp = (timestamp: number) => {
  const date = new Date(timestamp);
  const now = Date.now();
  const diff = now - timestamp;

  if (diff < 60000) return 'Just now';
  if (diff < 3600000) return `${Math.floor(diff / 60000)}m ago`;
  if (diff < 86400000) return `${Math.floor(diff / 3600000)}h ago`;
  return date.toLocaleDateString();
};

Problem

1. Timestamps from the Stellar blockchain are in seconds (Unix epoch), but Date.now() returns milliseconds
2. If timestamp is in seconds (e.g., 1711670400), new Date(1711670400) creates a date in January 1970 (interprets as milliseconds)
3. The diff would be massive, always falling through to toLocaleDateString(), showing "1/20/1970"
4. The tx-store.ts uses Date.now() (milliseconds) when recording transactions, but if any transaction data comes from the blockchain (seconds), units mismatch

Impact

• Transaction timestamps could show dates from 1970
• "Just now" and relative time formatting breaks for blockchain-sourced timestamps
• Users see incorrect transaction history timing

Suggested Fix

Add unit detection and normalization:

const formatTimestamp = (timestamp: number) => {
  // Normalize: if timestamp is in seconds (before year 2100 in ms), convert to ms
  const ms = timestamp < 1e12 ? timestamp * 1000 : timestamp;
  const date = new Date(ms);
  const diff = Date.now() - ms;

  if (diff < 60000) return 'Just now';
  if (diff < 3600000) return `${Math.floor(diff / 60000)}m ago`;
  if (diff < 86400000) return `${Math.floor(diff / 3600000)}h ago`;
  return date.toLocaleDateString();
};

File

frontend/src/components/wallet/TxHistory.tsx — Lines 77-91