feat: bulk label printing with QR codes and scan-to-expend

[crzykidd]

Major feature from PRD §10.7. Print physical labels for ammo boxes, optionally with a QR code that opens the box on a phone for quick round logging.

Scope

• Configurable label template — toggle any ammo_box field on/off, reorder via drag-and-drop, set field size (large/normal); saved as the default, overridable at print time.
• Avery label sizes — 5160 (30/sheet), 5163 (10/sheet), 5167 (80/sheet), 5164 (6/sheet).
• Optional QR code field — encodes the full URL to the box detail page (base URL from app.base_url in config.yaml); scanning opens the browser to that box (login redirect if needed).
• QR scan → expend flow (mobile-optimized) — box detail shows qty remaining with a progress bar and quick-expend buttons (Shot All (N) / 50 / 25 / 10 / 5 / custom); large targets for gloves/low light.
• Print flow — select boxes → Print Labels → choose size → preview → download PDF or send to browser print dialog.

Notes

• app.base_url already exists in config for the QR links.
• Depends on a PDF generation approach for the label sheets.

Source: PRD §10.7 (originally tagged v2.0).