chore(access): prune unwired readers, amend ADR-003 for what shipped

ADR-003, .env.example, the access module's headers and the provisioning
schema still described the planned npub-QR → UID → serial-reader path.
What shipped (#86) is Bolt Card tap-to-enter over the main-process
pcscd reader with external_id as the identity, soft entry and
verify-at-payment. Nothing ever called availableAccessReaders(): the
camera npub-QR reader, the mock reader and the AccessReader seam were
dead, so they go; services/access now holds authorize, the card parser
and the credential types. The unused 'uid' scan variant goes with them;
'npub' (+PIN) and the 'challenge' seam stay.

The ADR gets an amendment section recording the differences, including
that open enrollment is not a security boundary and that the audit is
still a stub (both tracked as issues).

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

docs/adr/003-nfc-access-control-layer.md

@@ -1,9 +1,24 @@
 # ADR-003: NFC Access-Control Layer (badge-to-enter) + Developer Bypass
 
-**Status:** Accepted
+**Status:** Accepted — amended 2026-09-20 (see [Amendment](#amendment-2026-09-20-what-shipped) below; the original text follows it unchanged)
 **Date:** 2026-07-29
 **Context:** batm3 gaining a physical access layer — an NFC card must be presented to unlock the machine before anyone can transact. Reader hardware is not yet on hand; this ADR defines the direction and a non-breaking skeleton that is fully testable without it.
 
+## Amendment (2026-09-20): what shipped
+
+The gate landed in aiolabs/bitspire#86 as **Bolt Card tap-to-enter**, not the npub-QR → UID → serial-reader path planned below. The decisions still stand (opt-in `locked` state, operator-owned authorization, hashed identities, fail-closed, audited); the mechanism differs:
+
+- **Reader.** The batm3 / upboard reader is a USB CCID contactless reader (Feitian KP382, OMNIKEY 5022) driven by `pcscd` + `nfc-pcsc` in the **main process** (`electron/nfc-service.ts`, from #83), not the serial `/dev/ttyNFC` device or Web NFC. Taps reach the renderer over the existing `nfc:card-tapped` IPC and the store routes them by state (`locked` → enter; the cash screens → pay / receive). The renderer-side `AccessReader` abstraction, the camera npub-QR reader and the mock reader were never wired to anything and have been removed; `services/access/` now holds only `authorize`, the Bolt Card parser and the credential types.
+- **Credential.** Identity is the card's boltcards `external_id`, parsed **locally** from the tapped `lnurlw` (`AccessScan` kind `boltcard`), not the NFC UID. Only `hashId(external_id, salt)` is compared or logged. The `npub` variant (with its PIN second factor) stays in `authorize()` and its tests for a future non-card credential; `challenge` remains the v2 seam; the planned `uid` variant is gone.
+- **Soft entry, verify-at-payment.** A tap yields a single-use SUN `p`/`c`. Verifying it at entry would spend the voucher we want to reuse at Complete, so entry makes **no server call**. The stored `lnurlw` is presented once, at Complete, through the #83 / #84 payment paths, and that is where the cryptographic check happens. Consequence: the loaded card is single-shot — after the first Complete attempt, accepted or declined, the store drops it and the customer re-taps.
+- **Open enrollment is not a security boundary.** With `openEnrollment` on (the current posture on every gated machine), any NDEF tag whose URL contains `/scan/<id>` unlocks the terminal. The gate keeps casual users off the menu; money still only moves on a valid SUN. Closing this — a provisioned allow-list, or a verify-at-entry variant that spends one tap — is tracked in aiolabs/bitspire#91.
+- **Session semantics.** One tap = one session; every transaction terminal state returns to `locked`. Inactivity (60 s on the idle menu) and the absolute cap (10 min) are measured at the DOM layer (`useSessionSecurity`) because an XState `after` cannot observe touches. Both send `END_SESSION`, which the machine accepts **from `idle` only**, so a timer can never abandon stacked bills or an in-flight dispense. An explicit End Session button re-locks immediately.
+- **Config.** `ACCESS_CONTROL_ENABLED` / `ACCESS_OPEN_ENROLLMENT` / `ACCESS_DEV_UNLOCK` / `ACCESS_SALT` from env, overridden by `/var/lib/bitspire/access.json` (pushed with `deploy/nixos/provision-access.sh`, no rebuild). `devUnlock` defaults **off**.
+- **Audit** is still a console stub; the state.db write promised in decision 7 is tracked in aiolabs/bitspire#90.
+- **Phased plan superseded.** PR3 (Web NFC) and PR4 (serial HAL) will not happen — the pcscd reader covers real hardware and there is no laptop dev path beyond the debug paste-box on `LockedView`. PR5's challenge-response idea survives as the `challenge` seam.
+
+---
+
 ## Decision
 
 1. **Add a top-level `locked` state to the ATM state machine, and make it the initial state.** It sits *below* the existing initialization gates (`unpaired` / `awaiting-fees` / `maintenance` / `signer-unreachable`, which live in `App.vue`). A healthy, paired machine boots into `locked` and only reveals `idle` (Buy/Sell) after an access grant.