Make gauge/maintenance identifiers per-asset-type and extend to all types

Optional asset identifiers (gauge lab reference, maintenance reference, FQDN)
were global per-identifier and only surfaced on equipment. Now they are
toggleable per asset type and rendered on every asset type.

- settings: replace 3 global identifier toggles with a per-type matrix. New
  keys identifier_<name>_<assettype>_enabled (3 identifiers x 4 types).
  IDENTIFIER_LABELS / IDENTIFIER_ASSETTYPES constants drive the seed (API seed
  and CLI seed settings).
- composable: identifierSettings now exposes isEnabled(name, assettype),
  per-type flag winning over the legacy global key, defaulting on.
- backend writes: computers, network, printers asset create + update now
  accept gaugelabreference and maintenancereference (equipment already did).
  Reads already flowed through Asset.to_dict.
- frontend: Settings page renders an identifier x asset-type toggle matrix.
  Equipment, PC, printer, network forms and detail pages show gauge/maintenance
  (and FQDN where applicable) gated by isEnabled(name, type).

Legacy global identifier_<name>_enabled keys are still honored as a fallback
for older installs. SystemSettings toggles upsert (create on 404) so a deploy
that has not re-seeded still works on first toggle.

144 tests pass, naming/style check green, frontend builds. Verified live:
matrix renders, PC form shows the fields, PUT persists gauge/maintenance on a
PC and reads back.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

shopdb/cli/__init__.py

@@ -361,6 +361,18 @@ def seed_settings():
         },
     ]
 
+    # Asset identifier toggles, per identifier AND per asset type (ADR-001).
+    from shopdb.core.api.settings import IDENTIFIER_LABELS, IDENTIFIER_ASSETTYPES
+    for name, label in IDENTIFIER_LABELS.items():
+        for assettype in IDENTIFIER_ASSETTYPES:
+            defaults.append({
+                'key': f'identifier_{name}_{assettype}_enabled',
+                'value': 'true',
+                'valuetype': 'boolean',
+                'category': 'identifiers',
+                'description': f'Show the {label} identifier on {assettype} assets',
+            })
+
     created = 0
     for d in defaults:
         if not Setting.query.filter_by(key=d['key']).first():