Frontend naming + CSS-variable cleanups (review low)

Naming convention (LOCKED): rename the ManifestEditor simulate state sim ->
simulateInputs / simResult -> simulateResult (+ .sim-result CSS class) - 'sim'
was banned standalone shorthand. Rename AssetRelationships props assetId ->
assetid and machineNumber -> machinenumber so a prop holding a DB field value
mirrors it verbatim; updated the five detail-page call sites (:assetid=).

CSS variables: SearchResults per-domain badge palette moved into CSS variables
on the container; the duplicated prefers-color-scheme dark block collapses to a
single set of variable overrides instead of restating all ten selectors.

frontend build green; vitest 49 pass; naming green; search badges + detail
relationships verified rendering with no console errors.

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

frontend/src/components/AssetRelationships.vue

@@ -196,12 +196,12 @@ import { apiError } from '../utils/apiError'
 const toast = useToast()
 
 const props = defineProps({
-  assetId: {
+  assetid: {
     type: Number,
     default: null
   },
   // Alternative: lookup by machine/asset number
-  machineNumber: {
+  machinenumber: {
     type: String,
     default: null
   }
@@ -315,14 +315,14 @@ onMounted(async () => {
   }
 })
 
-watch(() => props.assetId, async () => {
+watch(() => props.assetid, async () => {
   await resolveAssetId()
   if (resolvedAssetId.value) {
     await loadRelationships()
   }
 })
 
-watch(() => props.machineNumber, async () => {
+watch(() => props.machinenumber, async () => {
   await resolveAssetId()
   if (resolvedAssetId.value) {
     await loadRelationships()
@@ -330,17 +330,17 @@ watch(() => props.machineNumber, async () => {
 })
 
 async function resolveAssetId() {
-  // If assetId is provided directly, use it
-  if (props.assetId) {
-    resolvedAssetId.value = props.assetId
+  // If assetid is provided directly, use it
+  if (props.assetid) {
+    resolvedAssetId.value = props.assetid
     lookupFailed.value = false
     return
   }
 
   // Otherwise, try to look up by machine number
-  if (props.machineNumber) {
+  if (props.machinenumber) {
     try {
-      const response = await assetsApi.lookup(props.machineNumber)
+      const response = await assetsApi.lookup(props.machinenumber)
       resolvedAssetId.value = response.data.data?.assetid
       lookupFailed.value = !resolvedAssetId.value
     } catch (error) {