fix(hal): re-initialize dispenser after errors

After a dispense error, the F56/Puloon drivers call close() which sets
initialized=false. The next dispense would fail on a closed serial port.
Now checks dispenser.initialized before each dispense and re-inits if
needed, matching the lazy re-init pattern from brain.js (line 4072).

Closes #29

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

apps/machine/src/services/hal.ts

@@ -93,10 +93,11 @@ export async function initializeHalServices(config: HalConfig): Promise<HalServi
   })
 
   // Initialize dispenser
-  await dispenser.init({
+  const dispenserInitData = {
     fiatCode: valConfig.fiatCode,
     cassettes: dispConfig.cassettes,
-  })
+  }
+  await dispenser.init(dispenserInitData)
   console.log('[HAL] Dispenser initialized')
 
   // Start validator
@@ -121,6 +122,13 @@ export async function initializeHalServices(config: HalConfig): Promise<HalServi
     dispenseCash: async (amounts) => {
       console.log('[HAL] Dispensing:', amounts)
 
+      // Re-initialize dispenser if it was closed after a previous error
+      if (!dispenser.initialized) {
+        console.log('[HAL] Dispenser not initialized, re-initializing...')
+        await dispenser.init(dispenserInitData)
+        console.log('[HAL] Dispenser re-initialized')
+      }
+
       // Translate { denomination, count }[] to number[] by cassette position
       const notes: number[] = new Array(cassetteDenominations.length).fill(0)
       for (const { denomination, count } of amounts) {