fix(hal/ebds): poll MEI at 100ms, not 10s — bills were getting torn

EBDS is a host-polled protocol: the MEI validator only speaks when
polled, and its internal escrow grace expires after ~5 seconds. With
POLLING_INTERVAL=10_000 the host learned about an escrowed bill *after*
the MEI had already autonomously begun returning it, which on BATM3
hardware can shear the bill between the transport rollers and the
mouth (see torn $20 reported by operator).

Drop the interval to 100ms to match id003's cadence — so we see
escrow and issue stack/reject inside the validator's grace window.

This is the production-critical fix; observability + escrow watchdog
follow in subsequent commits.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/hal/src/validators/ebds/index.ts

@@ -17,7 +17,13 @@ import { EbdsFsm } from './ebds-fsm.js'
 import { denominations as denominationsTable } from './denominations.js'
 import type { BillValidator, ValidatorConfig, BillData } from '../../types.js'
 
-const POLLING_INTERVAL = 10_000
+// EBDS is host-polled: the validator only speaks when polled, and its
+// internal escrow grace expires after ~5s. Polling slower than that means
+// the host learns about an escrowed bill after the validator has already
+// auto-returned it, which on MEI hardware (BATM3) tears bills at the
+// transport rollers. Match id003's 100ms cadence so we see escrow inside
+// the validator's grace window.
+const POLLING_INTERVAL = 100
 
 /**
  * BigNumber-like interface for bill comparisons