feat(machine): persist exchange rate and currency in transactions

Add exchange_rate (sats per fiat unit) and currency columns to the
transactions table so transaction economics can be audited after the
fact. Includes schema migration v2 (fee columns) and v3 (rate/currency),
updated IPC types, and atm-transactions CLI output.

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

apps/machine/electron/state-store.ts

@@ -15,7 +15,7 @@ import fs from 'node:fs'
 
 let db: Database.Database | null = null
 
-const SCHEMA_VERSION = '1'
+const SCHEMA_VERSION = '3'
 
 function getDbPath(): string {
   const prodDir = '/var/lib/lamassu-atm'
@@ -68,6 +68,10 @@ export function initDatabase(dbPath?: string): void {
       type TEXT NOT NULL CHECK (type IN ('cash_in', 'cash_out')),
       fiat_cents INTEGER NOT NULL,
       sats INTEGER NOT NULL,
+      fee_sats INTEGER NOT NULL DEFAULT 0,
+      fee_percent REAL NOT NULL DEFAULT 0,
+      exchange_rate REAL NOT NULL DEFAULT 0,
+      currency TEXT NOT NULL DEFAULT 'GTQ',
       created_at INTEGER NOT NULL
     );
 
@@ -79,12 +83,31 @@ export function initDatabase(dbPath?: string): void {
     );
   `)
 
-  // Seed meta + cashbox if first run
+  // Seed meta + cashbox if first run, or run migrations
   const existing = db.prepare('SELECT value FROM meta WHERE key = ?').get('schema_version') as
     | { value: string }
     | undefined
   if (!existing) {
     db.prepare('INSERT INTO meta (key, value) VALUES (?, ?)').run('schema_version', SCHEMA_VERSION)
+  } else if (existing.value === '1') {
+    // Migration v1 → v2: add fee columns to transactions
+    db.exec(`
+      ALTER TABLE transactions ADD COLUMN fee_sats INTEGER NOT NULL DEFAULT 0;
+      ALTER TABLE transactions ADD COLUMN fee_percent REAL NOT NULL DEFAULT 0;
+    `)
+    db.prepare('UPDATE meta SET value = ? WHERE key = ?').run('2', 'schema_version')
+    console.log('[StateStore] Migrated schema v1 → v2 (added fee columns)')
+    existing.value = '2'
+  }
+
+  if (existing && existing.value === '2') {
+    // Migration v2 → v3: add exchange rate and currency
+    db.exec(`
+      ALTER TABLE transactions ADD COLUMN exchange_rate REAL NOT NULL DEFAULT 0;
+      ALTER TABLE transactions ADD COLUMN currency TEXT NOT NULL DEFAULT 'GTQ';
+    `)
+    db.prepare('UPDATE meta SET value = ? WHERE key = ?').run('3', 'schema_version')
+    console.log('[StateStore] Migrated schema v2 → v3 (added exchange_rate, currency)')
   }
 
   const cashboxRow = db.prepare('SELECT id FROM cashbox WHERE id = 1').get()
@@ -214,6 +237,10 @@ interface TransactionInput {
   type: 'cash_in' | 'cash_out'
   fiatCents: number
   sats: number
+  feeSats: number
+  feePercent: number
+  exchangeRate: number
+  currency: string
   bills: { denomination: number; count: number }[]
 }
 
@@ -224,7 +251,7 @@ export function recordTransaction(tx: TransactionInput): void {
   if (!db) throw new Error('Database not initialized')
 
   const insertTx = db.prepare(
-    'INSERT INTO transactions (txid, type, fiat_cents, sats, created_at) VALUES (?, ?, ?, ?, ?)'
+    'INSERT INTO transactions (txid, type, fiat_cents, sats, fee_sats, fee_percent, exchange_rate, currency, created_at) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)'
   )
   const insertBill = db.prepare(
     'INSERT INTO transaction_bills (txid, denomination, count) VALUES (?, ?, ?)'
@@ -237,7 +264,17 @@ export function recordTransaction(tx: TransactionInput): void {
   )
 
   const run = db.transaction((t: TransactionInput) => {
-    insertTx.run(t.txid, t.type, t.fiatCents, t.sats, Date.now())
+    insertTx.run(
+      t.txid,
+      t.type,
+      t.fiatCents,
+      t.sats,
+      t.feeSats,
+      t.feePercent,
+      t.exchangeRate,
+      t.currency,
+      Date.now()
+    )
 
     for (const bill of t.bills) {
       insertBill.run(t.txid, bill.denomination, bill.count)