feat: bake frontend commit hash into build (#9832)

## Summary

Bake the frontend git commit hash into the build so it no longer needs
to be fetched from the server via `/api/system_stats`.

## Changes

- **What**: Add `__COMFYUI_FRONTEND_COMMIT__` build-time constant (via
Vite `define`) sourced from `git rev-parse HEAD` at build time. Falls
back to `"unknown"` if git is unavailable. `SystemStatsPanel` uses this
baked-in value for the "Frontend Version" row in cloud mode instead of
the server-provided `comfyui_frontend_version` field.

## Testing
Confirmed to display the actual commit.
<img width="1448" height="908" alt="Screenshot 2026-03-12 at 7 09 52 PM"
src="https://github.com/user-attachments/assets/2b42348a-5c3e-4509-aa84-1a259bba5f3f"
/>


## Review Focus

- The `getDisplayValue` override for `comfyui_frontend_version` —
cleanest way to swap the data source without restructuring the column
system.
- No cloud-side changes needed: the `sync-frontend-build` workflow
already checks out the frontend repo at the exact commit ref, so `git
rev-parse HEAD` returns the correct hash.

src/components/common/SystemStatsPanel.vue

@@ -59,6 +59,8 @@ import type { SystemStats } from '@/schemas/apiSchema'
 import { formatCommitHash, formatSize } from '@/utils/formatUtil'
 import { cn } from '@/utils/tailwindUtil'
 
+const frontendCommit = __COMFYUI_FRONTEND_COMMIT__
+
 const props = defineProps<{
   stats: SystemStats
 }>()
@@ -77,6 +79,7 @@ type SystemInfoKey = keyof SystemStats['system']
 type ColumnDef = {
   field: SystemInfoKey
   header: string
+  getValue?: () => string
   format?: (value: string) => string
   formatNumber?: (value: number) => string
 }
@@ -104,6 +107,7 @@ const cloudColumns: ColumnDef[] = [
   {
     field: 'comfyui_frontend_version',
     header: 'Frontend Version',
+    getValue: () => frontendCommit,
     format: formatCommitHash
   },
   { field: 'workflow_templates_version', header: 'Templates Version' }
@@ -119,7 +123,9 @@ function isOutdated(column: ColumnDef): boolean {
 }
 
 function getDisplayValue(column: ColumnDef) {
-  const value = systemInfo.value[column.field]
+  const value = column.getValue
+    ? column.getValue()
+    : systemInfo.value[column.field]
   if (column.formatNumber && typeof value === 'number') {
     return column.formatNumber(value)
   }