Add the printedparts plugin: 3D-printed parts storefront and kiosk

Catalog with photos and append-only print-file revisions, a stock
ledger attributing every take/restock/adjust to a badge-resolved
employee, a touch kiosk (scan bin, scan badge, keypad quantity) with a
deliberately open decrement-only take endpoint, 1x0.5in CODE128 bin
labels, low-stock email alerts to selected users, roles, or addresses,
and stock/consumption/by-person reports with a cache-vs-ledger
reconcile. Ships disabled; enable per site. Contract 0.13.0 adds the
mailer and the User/Role models to the plugin surface.

plugins/printedparts/README.md

@@ -0,0 +1,59 @@
+# Printedparts plugin
+
+3D-printed parts inventory + kiosk checkout
+
+This plugin was generated by `flask plugin new printedparts`. It satisfies the framework contract out of the box. Replace the example model and routes with your domain.
+
+## What's here
+
+- `plugin.py` - the `PrintedpartsPlugin` class extending `BasePlugin`. Edit `init_app` for custom setup, `on_install` to seed reference data.
+- `models/printedparts.py` - example Asset extension table. Replace `examplefield` with your domain fields.
+- `api/routes.py` - example list and detail endpoints. Add CRUD as needed.
+- `schemas/__init__.py` - marshmallow schema stub for request/response validation.
+- `tests/test_plugin.py` - smoke tests asserting contract compliance.
+- `manifest.json` - plugin metadata. Bump `version` on changes; keep `core_version` range broad.
+
+## Common edits
+
+| You want to... | Do this |
+|---|---|
+| Add a hook (search, navigation, dashboard widget) | Override the method in `PrintedpartsPlugin`. See the PLUGIN-HOOKS wiki page. |
+| Accept external collector data | Override `get_collector_schema()` to return a JSON Schema. See ADR-006. |
+| Add another model | Create `models/<other>.py`, export it in `models/__init__.py`, return it in `get_models()`. |
+| Add a CLI command | Override `get_cli_commands()` returning a list of Click commands. |
+
+## Frontend
+
+Vue components for this plugin live under `frontend/src/views/printedparts/` (per project convention). Backend scaffolding does not generate frontend yet; copy from an existing plugin's view files (e.g., `frontend/src/views/network/`) as a starting point.
+
+## Install and run
+
+```bash
+flask plugin install printedparts
+flask db migrate -m "Add printedparts plugin tables"
+flask db upgrade
+pytest plugins/printedparts/tests/
+```
+
+## References
+
+- the PLUGIN-HOOKS wiki page - canonical hook reference
+- the PLUGIN-QUICKSTART wiki page - 30-minute walkthrough
+- `migrations/adr/ADR-001-asset-as-platform-contract.md` - the platform contract
+- `migrations/adr/ADR-002-plugin-versioning.md` - versioning rules
+
+## Why the kiosk take endpoint is unauthenticated
+
+`POST /api/printedparts/kiosk/take` is the product's first open WRITE (every
+other kiosk endpoint is a read). Accepted deliberately, against the criteria
+in docs/proposals/printedparts-plugin.md:
+
+1. Decrement-only: it can reduce stock of an active item, nothing else.
+2. Fully attributed: it refuses to act without a badge that resolves under
+   the site policy; every action lands in the ledger with SSO + name + time.
+3. Bounded blast radius: worst case is stock counts driven low - visible in
+   the ledger and reversible with an adjust.
+4. Physically rate-limited: it serves a touch screen on the shop floor;
+   nothing enumerable, nothing worth scraping.
+
+Any future open-write endpoint must clear the same bar.