Contract 0.12.0: send_email/send_alert join the plugin surface (the
mailer was core-only), PLUGIN-HOOKS and status docs updated, manifest
pins the new floor. The alert fires inside _ledger_write only when a
decrement CROSSES the item's threshold - one alert per depletion,
rearmed by restocking above - and is best-effort after the commit so
mail trouble can never fail a take. Recipients come from
printedparts_alert_email, falling back to the site alert_recipients.
on_enable re-seeds settings idempotently so existing installs pick up
new keys. Crossing/rearm semantics proven by test.
The lab is now a build-along mirroring what actually happened: ten
stages, each with the goal, the divergences, a see-it-work check, and
the errors genuinely hit while building (empty Migration error from a
broken model import, the migration-guard KeyError, the missing Lucide
icon, nested-app-context test writes, Decimal sums, and the authz
sweep catching the deliberately open kiosk take). That last one gets
its explicit EXEMPT_ENDPOINTS entry with a pointer to the decision
record - the net stays, the exception is reviewable. Full suite: 993
backend tests, 49 vitest, frontend build, naming hook, all green.
State that this is a bundled plugin whose frontend and three small core
edits land in this repo, list the three deliberate divergences from the
scaffold before the learner hits them, suggest a per-milestone solution
branch for instructors, and point out the earliest visible win (wire
the bare list page as soon as the GET endpoint works).
The kiosk take endpoint is the product's first unauthenticated
mutation; spell out the acceptance criteria (decrement-only, badge
attributed, bounded, physically rate-limited) so future open-write
endpoints meet the same bar. The dashboard-widget milestone is marked
optional: get_dashboard_widgets predates the ADR-010 data-only
renderers and needs a core component to render.
Design for a 3D-printed-parts storefront: item catalog with images and
quantity on hand, a transaction ledger attributing every take/restock/
adjust to a badge-scanned employee, an unauthenticated touch kiosk
(scan bin barcode, scan badge, keypad quantity), 1x0.5in CODE128 bin
labels, and stock/consumption/by-person reports.
The lab guide walks a developer through building it in seven
checkpointed milestones, reusing the USB badge contract, the
measuringtools migration baseline, the models-image upload trio, and
the open kiosk-endpoint precedents.
