fix(hal): make validator optional for dispenser-only operation

The HAL init hung indefinitely when the validator device didn't exist
or failed to respond — blocking the entire init including the dispenser
and Lightning connection.

Now the validator is optional:
- Checks device exists (fs.existsSync) before attempting to open
- 15s timeout on validator.run() to prevent hanging
- On failure, logs warning and proceeds with dispenser-only mode
- All validator methods guarded with null checks

This enables the BATM3 to run cash-out only when the MEI validator
is not connected (e.g., during initial setup or testing).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/machine/electron/hal-service.ts

@@ -68,11 +68,6 @@ export async function initializeHal(config: HalConfig): Promise<HalInstance> {
   const { validator: valConfig, dispenser: dispConfig } = config
 
   // Create hardware instances
-  const validator: BillValidator = hal.createValidator(valConfig.type, {
-    rs232: { device: valConfig.device, fiatCode: valConfig.fiatCode },
-    fiatCode: valConfig.fiatCode,
-  })
-
   const dispenser: BillDispenser = hal.createDispenser(dispConfig.type, {
     device: dispConfig.device,
   })
@@ -85,14 +80,35 @@ export async function initializeHal(config: HalConfig): Promise<HalInstance> {
   await dispenser.init(dispenserInitData)
   console.log('[HAL] Dispenser initialized')
 
-  // Start validator
+  // Start validator (optional — proceed without if device is missing or fails)
+  let validator: BillValidator | null = null
+  try {
+    const fs = await import('node:fs')
+    const device = Array.isArray(valConfig.device) ? valConfig.device[0] : valConfig.device
+    if (device && fs.existsSync(device)) {
+      validator = hal.createValidator(valConfig.type, {
+        rs232: { device: valConfig.device, fiatCode: valConfig.fiatCode },
+        fiatCode: valConfig.fiatCode,
+      })
+
       await new Promise<void>((resolve, reject) => {
-    validator.run((err?: Error) => {
+        const timeout = setTimeout(() => {
+          reject(new Error('Validator init timed out'))
+        }, 15000)
+        validator!.run((err?: Error) => {
+          clearTimeout(timeout)
           if (err) return reject(err)
           resolve()
         })
       })
       console.log('[HAL] Validator started')
+    } else {
+      console.log('[HAL] Validator device not found, running dispenser-only')
+    }
+  } catch (err) {
+    console.warn('[HAL] Validator failed to start, running dispenser-only:', err)
+    validator = null
+  }
 
   // Track inventory
   const inventory: Record<number, number> = {}
@@ -104,6 +120,10 @@ export async function initializeHal(config: HalConfig): Promise<HalInstance> {
 
   return {
     connectValidator: (callbacks: ValidatorCallbacks) => {
+      if (!validator) {
+        console.log('[HAL] No validator — cash-in disabled')
+        return
+      }
       validator.on('billsRead', (data: { denomination: number | null; code: number }) => {
         if (data.denomination !== null) {
           const decision = callbacks.shouldAcceptBill(data.denomination)
@@ -142,17 +162,17 @@ export async function initializeHal(config: HalConfig): Promise<HalInstance> {
     },
 
     enableValidator: () => {
-      validator.enable()
-      validator.lightOn()
+      validator?.enable()
+      validator?.lightOn()
     },
 
     disableValidator: () => {
-      validator.disable()
-      validator.lightOff()
+      validator?.disable()
+      validator?.lightOff()
     },
 
-    stackBill: () => validator.stack(),
-    rejectBill: () => validator.reject(),
+    stackBill: () => validator?.stack(),
+    rejectBill: () => validator?.reject(),
 
     dispenseCash: async (amounts): Promise<DispenseResult> => {
       console.log('[HAL] Dispensing:', amounts)
@@ -229,13 +249,17 @@ export async function initializeHal(config: HalConfig): Promise<HalInstance> {
 
     cleanup: async () => {
       return new Promise<void>((resolve) => {
-        validator.disable()
-        validator.lightOff()
+        validator?.disable()
+        validator?.lightOff()
         dispenser.close()
+        if (validator) {
           validator.close((err?: Error) => {
             if (err) console.error('[HAL] Validator close error:', err)
             resolve()
           })
+        } else {
+          resolve()
+        }
       })
     },
   }