fix: eradicate tailwind @apply usage in vue styles (#9146)

## Summary

Remove Tailwind `@apply` from Vue styles across `src/` and
`apps/desktop-ui/src/` to align with Tailwind v4 guidance, replacing
usages with template utilities or native CSS while preserving behavior.

## Changes

- **What**:
- Batch 1: migrated low-risk template/style utility bundles out of
`@apply`.
- Batch 2: converted PrimeVue/`:deep()` override `@apply` blocks to
native CSS declarations.
- Batch 3: converted `src/components/node/NodeHelpContent.vue` markdown
styling from `@apply` to native CSS/token-based declarations.
- Batch 4: converted final desktop pseudo-element `@apply` styles and
removed stale `@reference` directives no longer required.
- Verified `rg -n "^\s*@apply\b" src apps -g "*.vue"` has no real CSS
`@apply` directives remaining (only known template false-positive event
binding in `NodeSearchContent.vue`).

## Review Focus

- Visual parity in components that previously depended on `@apply` in
`:deep()` selectors and markdown content:
  - topbar tabs/popovers, dialogs, breadcrumb, terminal overrides
  - desktop install/dialog/update/maintenance surfaces
  - node help markdown rendering
- Confirm no regressions from removal of now-unneeded `@reference`
directives.

## Screenshots (if applicable)

- No new screenshots included in this PR.
- Screenshot Playwright suite was run with `--grep="@screenshot"` and
reports baseline diffs in this environment (164 passed, 39 failed, 3
skipped) plus a teardown `EPERM` restore error on local path
`C:\Users\DrJKL\ComfyUI\LTXV\user`.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-9146-fix-eradicate-tailwind-apply-usage-in-vue-styles-3116d73d3650813d8642e0bada13df32)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Amp <amp@ampcode.com>
Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

src/components/breadcrumb/SubgraphBreadcrumb.vue

@@ -195,8 +195,6 @@ onUpdated(() => {
 </script>
 
 <style scoped>
-@reference '../../assets/css/style.css';
-
 .subgraph-breadcrumb:not(:empty) {
   flex: auto;
   flex-shrink: 10000;
@@ -205,7 +203,7 @@ onUpdated(() => {
 
 .subgraph-breadcrumb,
 :deep(.p-breadcrumb) {
-  @apply overflow-hidden;
+  overflow: hidden;
 }
 
 :deep(.p-breadcrumb) {
@@ -214,7 +212,10 @@ onUpdated(() => {
 }
 
 :deep(.p-breadcrumb-item) {
-  @apply flex items-center overflow-hidden h-8;
+  display: flex;
+  align-items: center;
+  overflow: hidden;
+  height: calc(var(--spacing) * 8);
   min-width: calc(var(--p-breadcrumb-item-min-width) + 1rem);
   border: 1px solid transparent;
   background-color: transparent;
@@ -236,7 +237,7 @@ onUpdated(() => {
 }
 
 :deep(.p-breadcrumb-item:hover) {
-  @apply rounded-lg;
+  border-radius: var(--radius-lg);
   border-color: var(--interface-stroke);
   background-color: var(--comfy-menu-bg);
 }
@@ -270,18 +271,16 @@ onUpdated(() => {
 </style>
 
 <style>
-@reference '../../assets/css/style.css';
-
 .subgraph-breadcrumb-collapse .p-breadcrumb-list {
   .p-breadcrumb-item,
   .p-breadcrumb-separator {
-    @apply hidden;
+    display: none;
   }
 
   .p-breadcrumb-item:nth-last-child(3),
   .p-breadcrumb-separator:nth-last-child(2),
   .p-breadcrumb-item:nth-last-child(1) {
-    @apply flex;
+    display: flex;
   }
 }
 </style>

src/components/breadcrumb/SubgraphBreadcrumbItem.vue

@@ -186,19 +186,19 @@ const inputBlur = async (doRename: boolean) => {
 </script>
 
 <style scoped>
-@reference '../../assets/css/style.css';
-
 .p-breadcrumb-item-link,
 .p-breadcrumb-item-icon {
-  @apply select-none;
+  user-select: none;
 }
 
 .p-breadcrumb-item-link {
-  @apply overflow-hidden;
+  overflow: hidden;
 }
 
 .p-breadcrumb-item-label {
-  @apply whitespace-nowrap text-ellipsis overflow-hidden;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
 }
 
 .active-breadcrumb-item {