v1.22.0: POS completions and dockd reads

"POS completions and dockd reads" release. Two threads.

The POS sale path is rounded out -- shipping charges and ship method persist on the order, split (part cash + part card) tender is accepted, and a full refund now cancels the original sale instead of leaving it SHIPPED. And the dockd warehouse-floor integration gains a barcode item-lookup endpoint plus the ordered quantity on its order payload.

Mobile. Zero mobile/ diffs on this release. The current mobile build (version 1.19.0, versionCode 9) remains current; no new APK for v1.22.0.

Added

• POS shipping charge, ship method, and totals (#399): the payment summary gains shipping_cents (default 0, preserving the counter-sale contract) and checkout gains an optional ship_method. On a phone order the shipping charge persists to sales_orders.customer_shipping_paid, the operator-selected method to ship_method, and the order total to order_total, so the picking ticket and downstream consumers see real freight figures. A full refund credits the shipping back with the order: the credit-memo SO stores negative order_total and customer_shipping_paid to mirror its negative credit lines.
• POS split tender (#400): split is accepted as a PaymentSummary.method for a part-cash + part-card sale; the tenders list carries the per-method breakdown and the refund path matches it symmetrically (split sale -> split refund). Additive under the DRAFT-v1 POS contract.
• dockd item lookup + ordered quantity (#401): GET /api/v1/dockd/items/<barcode> resolves an item by barcode (UPC) and returns its canonical detail plus per-location stock, scoped to the token's warehouses; gated as a dockd inbound resource like the other dockd reads. The dockd GET order payload also returns qty_ordered alongside the fulfilled qty on each line. The OpenAPI spec and docs/api/dockd-openapi.yaml are regenerated to match (parity test enforced).

Fixed

• POS refund cancels the original SO (#402): a v1 refund is full-order only, so a refunded sale is now a cancelled sale -- the original SO moves to status=CANCELLED (keeping the refunded_at + refund_so_id link) so admin and picker views stop showing it as SHIPPED. The "must be SHIPPED" state gate moves below the already-refunded check, so a repeat refund attempt surfaces 422 already_refunded instead of 404-ing on the now-CANCELLED status.