Put the dual-bay sibling in the triage band, and fix the gage counterpart

TWO STRIPS OF CHROME SAYING THE SAME KIND OF THING

The machine page opened with a banner - "Dual-bay machine - sibling bay: 2022" -
directly above a hero whose band said "Controlled by". Both answer "what am I
looking at", and splitting them across a banner and a band cost a strip of
vertical space to say so.

The sibling is now a chip in the band beside the controlling PC. The band takes
an `extraitems` prop rather than learning what dualpath is: the pairing is
resolved by the machines plugin, not from the relationships endpoint, so core
cannot derive it, and a dualpath-shaped prop on a core component would be the
machines plugin leaking upward. A page passes [{label, links:[{text, to}]}] and
the band renders it with its own markup, which also keeps the chips visually
identical to the ones it derives itself.

The label stays "Dual-bay sibling" rather than "Dualpath". The banner spelled
the meaning out because a dualpath pair is ONE physical machine in two bays; a
chip reading "Dualpath" would have dropped that.

THE GAGE PAGE FILTERED FOR A COUNTERPART THAT CANNOT EXIST

MeasuringToolDetail was wired counterparttype="machine" labelled "Used on".
Wrong on both counts. The import synthesizes one measuring-tool asset per
metrology PC and a 'controls' edge PC -> tool (stage_metrology), so a gage's
counterpart is a COMPUTER, exactly as on the machine page. Filtering for a
machine peer meant the band rendered nothing on every gage that has a PC.

It looked merely empty rather than wrong because this dev database holds one
measuring tool with no relationships at all, so there was nothing to be missing.
A hand-held gage genuinely has no such edge and correctly shows nothing; a
metrology station now shows the PC that drives it.

The relationships card stays. It is the only surface with Add Relationship and
the per-row delete, and it lists types the band filters out - the band is
triage, the card is management. It does now repeat what the band shows, which
is worth revisiting separately.

Verified on screen. Frontend 280 passed.

frontend/src/components/AssetTriageBand.vue

@@ -19,6 +19,20 @@
       </span>
     </div>
 
+    <div v-for="item in extraitems" :key="item.label" class="triage-item">
+      <span class="triage-label">{{ item.label }}</span>
+      <span class="triage-values">
+        <component
+          v-for="link in item.links"
+          :key="link.text"
+          :is="link.to ? 'router-link' : 'span'"
+          :to="link.to || undefined"
+          class="triage-chip"
+          :class="{ link: Boolean(link.to) }"
+        >{{ link.text }}</component>
+      </span>
+    </div>
+
     <div v-if="accessmethods && accessmethods.length" class="triage-item">
       <span class="triage-label">Remote access</span>
       <span class="triage-values">
@@ -86,7 +100,15 @@ const props = defineProps({
   // printer through usesprinter and defaultprinter. Hardcoding 'controls'
   // left the band blank on the printer page, which is the one page where the
   // link is not obvious from the asset itself.
-  relationshiptypes: { type: Array, default: () => ['controls'] }
+  relationshiptypes: { type: Array, default: () => ['controls'] },
+  // Triage facts a page knows but core cannot derive from a relationship
+  // edge. The machine page's dual-bay sibling is the case this exists for:
+  // it is resolved by the machines plugin, not from the relationships
+  // endpoint, and it used to sit in its own banner above the hero - two
+  // strips of chrome saying two halves of the same "what am I looking at".
+  // Shape: [{ label, links: [{ text, to }] }]. A link with no `to` renders
+  // as plain text rather than a dead chip.
+  extraitems: { type: Array, default: () => [] }
 })
 
 const machines = ref([])
@@ -102,6 +124,7 @@ const hasAnything = computed(() =>
   Boolean(slots.actions) ||
   Boolean(props.liveness) ||
   machines.value.length > 0 ||
+  props.extraitems.length > 0 ||
   (props.accessmethods && props.accessmethods.length > 0) ||
   Boolean(props.locationname)
 )