docs: finish the LNbits-era doc sweep across docs/ + .claude/skills/

Second + final batch of the doc refresh. README + CLAUDE went out in
8c9ae29; deploy/nixos/README + obsolete-flow flags in 924844f. This
commit covers everything left.

docs/machine-installation.md
  Was describing a manual AppImage scp deploy + a `lamassu-kiosk`
  systemd unit that hasn't been the deployment path for months.
  Replaced with a high-level "what the pipeline does and why"
  overview that points at deploy/nixos/README.md for the full
  command-by-command walkthrough. Includes the BATM3 chassis-mod
  note (custom Dell OptiPlex retrofit, not a stock Dell).

docs/architecture-comparison.md
  Rewrote the comparison to be lamassu-server (≤ v8.1.5) vs bitSpire
  (LNbits-backed) instead of the original lamassu-server vs LP-backed
  lamassu-next framing. Updated the cash-out + cash-in flow diagrams
  to show the actual nostr-transport path (LNbits-bundled nostrrelay
  extension at ws://<host>:5001/nostrrelay/test, no separate strfry
  container). Replaced the migration-path section with a softer
  "when to choose what" framing that includes Lamassu's current
  commercial offering as a legitimate third option. Added a header
  pointer to the Acknowledgements section.

docs/business-model.md
  Light touch-ups: Lightning.Pub → LNbits where it appeared, swapped
  the [[ndebit-cash-in-flow]] link for [[architecture-comparison]],
  noted the kind-30078 service beacon for availability broadcasts.

docs/device-configuration.md
  Dropped "Lamassu" branding from the machine-model headings
  (Sintra / tejo / douro / batm3 are referenced by hardware identity
  here, not by Lamassu's product line). Added the Sintra-specific
  ttyS4-vs-placeholder-ttyS1..3 gotcha we hard-learned during the
  first flash. Corrected the BATM3 entry: stock GeneralBytes chassis
  with a Dell OptiPlex 9030 AIO motherboard physically grafted in,
  NOT a Dell out of the box. Updated the example /dev/ttyJ* symlink
  output to match what a healthy Sintra actually shows.

docs/adr/001-hal-architecture.md
  ADRs are historical artifacts — kept the original decision text
  intact. Added a postscript noting:
    - The package rename @lamassu/hal → @bitSpire/hal
    - The v8.1.5 boundary on any lamassu-machine source-tree
      references (Lamassu's 2024-01-26 license transition)
    - That the "Remaining Work" list is complete and the first
      successful Sintra hardware integration ran on 2026-05-13

.claude/skills/lightning-check.md
  Rewrote end-to-end. Was Lightning.Pub-flavoured with CLINK kinds
  21001/21002 as the primary flows; now validates the LNbits nostr-
  transport surface (kind-21000 envelope, NIP-44 v2 encryption,
  subscribe_payments filter discipline, lnurlw link composition).
  Preserved a --clink mode for the still-live kind-21003 operator-
  management surface. Includes a "what to check" rubric for cash-out
  vs cash-in flows that mirrors the actual code in
  apps/machine/src/services/lightning.ts.

.claude/skills/hal-check.md
  Two pivots: (1) acknowledge ADR-001's TypeScript-not-Rust choice
  and reframe all the safety checklists in TS-flavour (type safety,
  discriminated unions, single-writer serial, bounded emitters)
  instead of Rust-flavour (unsafe, borrow checker). (2) Add explicit
  v8.1.5 provenance boundary plus a "forbidden operations" section
  that prohibits diffing or porting from v8.1.6+ lamassu-machine
  source. Updated the port-validation source-reference table to
  list TS file paths under packages/hal/ instead of Rust paths.

.claude/skills/docs.md
  @lamassu/* → @bitSpire/*. Replaced the Lightning.Pub mermaid
  diagram with a current cash-out flow showing the nostr-transport
  RPC + subscribe_payments push path. Left the createOffer noffer
  example in the API-docs template section since it's illustrative
  ("here's what a good TSDoc block looks like") rather than current
  reference documentation.

.claude/skills/test.md
  One-line: @lamassu/nostr-client → @bitSpire/nostr-client in the
  pnpm-filter example.

deploy/nixos/README.md
  Single touch-up: clarified the douro/batm3 hardware-module comments
  to reflect that BATM3 is a custom-installed Dell board in a
  GeneralBytes BATM3 chassis (not a Dell OEM).

Files NOT touched in this sweep (intentionally):
  - packages/hal/src/**/*.ts attribution comments — those reference
    "lamassu-machine" in their port-source headers. Those are
    factually accurate (the drivers ARE ported from there, up to
    v8.1.5) and constitute necessary license/attribution metadata.
    Editing them would erase the provenance trail.
  - .claude/skills/{nostr-check,security}.md — already protocol-
    neutral, no LP/lamassu references to clean up.

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

.claude/skills/docs.md

@@ -25,10 +25,11 @@ docs/
 │   ├── lightning-flow.md    # Payment flows
 │   └── hardware-hal.md      # HAL documentation
 ├── api/
-│   ├── nostr-client.md      # @lamassu/nostr-client API
-│   ├── clink.md             # @lamassu/clink API
-│   ├── state-machine.md     # @lamassu/state-machine API
-│   └── hal.md               # @lamassu/hal API
+│   ├── nostr-client.md      # @bitSpire/nostr-client API
+│   ├── lnbits.md            # @bitSpire/lnbits API (kind-21000 RPC surface)
+│   ├── clink.md             # @bitSpire/clink API (dormant on dev; 21003 management still wired)
+│   ├── state-machine.md     # @bitSpire/state-machine API
+│   └── hal.md               # @bitSpire/hal API
 ├── guides/
 │   ├── development.md       # Dev setup guide
 │   ├── hardware-testing.md  # Testing with real hardware
@@ -106,22 +107,25 @@ Keep architecture diagrams current:
 
 ```mermaid
 sequenceDiagram
-    participant U as User
+    participant U as Customer Wallet
     participant A as ATM
-    participant R as Relay
-    participant L as Lightning.Pub
+    participant R as Relay (LNbits-bundled nostrrelay)
+    participant L as LNbits (nostr-transport)
 
-    U->>A: Insert $20 bill
-    A->>A: Validate bill
-    A->>R: Publish CLINK offer
-    U->>R: Send payment request
-    R->>A: Forward request
-    A->>L: Generate invoice
-    L->>A: Return invoice
-    A->>R: Send invoice to user
-    U->>L: Pay invoice
-    L->>A: Payment confirmed
-    A->>U: Display success
+    Note over A,L: cash-out flow (customer pays ATM, gets cash)
+    A->>R: kind-21000 RPC "create_invoice"
+    R->>L: forward to LNbits server pubkey
+    L->>R: kind-21000 ACK with BOLT11 invoice
+    R->>A: forward ACK
+    A->>U: display BOLT11 QR
+    A->>R: kind-21000 "subscribe_payments" by payment_hash
+    R->>L: forward
+    L->>R: kind-21000 ACK with subscription_id
+    R->>A: forward
+    U->>L: pay BOLT11 via Lightning Network
+    L->>R: kind-21000 push (settlement) tagged subscription_id
+    R->>A: forward
+    A->>A: dispense cash
 ```
 
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