ADR-013 Phase 3: search routes via get_asset_presentation, not a hardcoded map

Global-search rows built the plugin detail URL from a hardcoded url_map of
plugin routes in core. Now core prefers a plugin's declared
get_asset_presentation route (ADR-010), substituting the core assetid via the
plugin's by-asset resolver; types that have not declared fall back to the legacy
id-keyed map, so nothing breaks. Measuring tools (which declare the route) link
through it now; machines/PCs/printers/network migrate off the hardcode as they
add a by-asset route + declaration. Presentation map is collected once per
search (cached on flask.g). 2 consumer tests; 26 search tests green.

tests/test_core/test_search_presentation.py

@@ -0,0 +1,47 @@
+"""Search consumes get_asset_presentation for plugin-owned routes (ADR-010).
+
+Core no longer hardcodes a plugin's search route once the plugin declares one:
+measuring tools (which declare a by-asset presentation route) link through it,
+while a type that has not declared falls back to the legacy id-keyed route.
+"""
+
+from types import SimpleNamespace
+
+from shopdb.core.api.search import _get_asset_result
+
+
+def _fake_asset(assettype, assetid, **extra):
+    asset = SimpleNamespace(
+        assettype=SimpleNamespace(assettype=assettype),
+        assetid=assetid,
+        display_name=f'{assettype}-{assetid}',
+        name=None,
+        assetnumber=f'AN{assetid}',
+        location=None,
+        machine=None, computer=None, network_device=None, printer=None,
+        measuringtool=None,
+    )
+    for key, value in extra.items():
+        setattr(asset, key, value)
+    return asset
+
+
+def test_measuring_tool_uses_declared_presentation_route(app):
+    """A declared by-asset route is used, keyed on the core assetid."""
+    with app.app_context():
+        tool = _fake_asset(
+            'measuring_tool', 641,
+            measuringtool=SimpleNamespace(measuringtoolid=99))
+        result = _get_asset_result(tool, 'x')
+    assert result['url'] == '/measuringtools/by-asset/641'
+    assert result['id'] == 641
+
+
+def test_machine_falls_back_to_legacy_route(app):
+    """A type with no declared presentation keeps the legacy id-keyed route."""
+    with app.app_context():
+        machine = _fake_asset(
+            'machine', 80, machine=SimpleNamespace(machineid=12))
+        result = _get_asset_result(machine, 'x')
+    assert result['url'] == '/machines/12'
+    assert result['id'] == 12