Multi-site distribution readiness: settings-driven site config, security closeout, release engineering, v0.5.0

Make the app distributable to other GE Aerospace sites (one self-hosted
instance per site, ADR-004). GE values remain the shipped defaults; every
site-specific behavior is now a Setting an admin can change in the UI.

Settings-driven site config:
- Branding: site/QR/badge logos, favicon, primary color (upload endpoints
  mirror the map-blueprint pattern; new Settings > Branding section).
- ServiceNow: search/incident/change URL templates ({ticket}), ticket
  prefixes, enable toggle. Defaults point at the current
  geaerospaceqa.service-now.com global search. Disabled = plain-text tickets.
- Employee-id regex (employeeid_pattern), printer hostname template,
  QR label targets (qr_target_printer / qr_target_usb, blank = asset page,
  else URL template with placeholders), usb_label_style (barcode|qr).
- West Jefferson floor-plan PNGs removed from the tree; generic placeholder
  ships as the map default and sites upload their own blueprint.

Security closeout:
- dashboarddefaults writes now require admin.
- Collector: generic error messages (no str(exc) leak); API key accepted
  via X-API-Key header only (BREAKING: querystring api_key removed).
- IP-based login rate limiting (AUTH_RATELIMIT_* knobs) atop account lockout.
- Setting.set() creation race fixed (IntegrityError retry).

Release engineering and docs:
- __version__ 0.5.0 (distinct from __contract_version__, ADR-007),
  CHANGELOG.md, Gitea Actions CI config, frontend version aligned.
- One wizard-first install story across README/DEPLOY; new CONFIG.md,
  UPGRADE.md, BACKUP-RESTORE.md; CLAUDE.md and ROADMAP de-staled.
- Dockerfile multi-stage build now bundles the frontend; compose binds
  MySQL to 127.0.0.1; stale database/schema.sql and one-off SQL removed.

Debt and fixes:
- .query.get() -> db.session.get() sweep; datetime.utcnow() removed
  (naive-UTC via timezone-aware now); users.py on authz decorators.
- Fixed 4 stale tests (slides feed shape, shopfloor splitperemployee,
  plugin contract purity) and the USB label page field mapping (both usb
  modes emit the cmmc shape: device_id/device_desc).
- Health endpoint reports the real version.

248 tests pass; naming/style check green; frontend builds; fresh-DB
flask db upgrade + seeds verified; QR targets verified by decoding
rendered codes.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

shopdb/plugins/registry.py

@@ -4,7 +4,7 @@ import json
 from pathlib import Path
 from typing import Dict, List, Optional
 from dataclasses import dataclass, field, asdict
-from datetime import datetime
+from datetime import datetime, timezone
 
 
 @dataclass
@@ -59,7 +59,7 @@ class PluginRegistry:
         state = PluginState(
             name=name,
             version=version,
-            installed_at=datetime.utcnow().isoformat(),
+            installed_at=datetime.now(timezone.utc).replace(tzinfo=None).isoformat(),
             enabled=enabled
         )
         self._plugins[name] = state