add build version tracking with commit SHA, version number, and build timestamp to frontend

frontend/vite.config.ts

@@ -3,8 +3,22 @@ import react from '@vitejs/plugin-react'
 import tailwindcss from '@tailwindcss/vite'
 import { VitePWA } from 'vite-plugin-pwa'
 
+const appVersion = process.env.npm_package_version ?? '0.0.0'
+const appCommit = (
+  process.env.GITEA_SHA ??
+  process.env.GITHUB_SHA ??
+  process.env.COMMIT_SHA ??
+  'dev'
+).slice(0, 12)
+const appBuiltAt = new Date().toISOString()
+
 // https://vite.dev/config/
 export default defineConfig({
+  define: {
+    __APP_VERSION__: JSON.stringify(appVersion),
+    __APP_COMMIT__: JSON.stringify(appCommit),
+    __APP_BUILT_AT__: JSON.stringify(appBuiltAt),
+  },
   plugins: [
     react(),
     tailwindcss(),
@@ -35,4 +49,4 @@ export default defineConfig({
       },
     },
   },
-})
+})