Register arrow-right and check-circle-2 icons for pipeline strip

astro-icon requires explicit icon registration — these two were used
in PipelineStrip.astro but missing from the include list, causing
SSR render failures in production.

frontend/astro.config.mjs

@@ -9,7 +9,7 @@ export default defineConfig({
   adapter: node({ mode: 'standalone' }),
   integrations: [
     react(),
-    icon({ include: { lucide: ['plus', 'book-open', 'zap', 'cpu', 'activity', 'circuit-board', 'file-text', 'chevron-down'] } }),
+    icon({ include: { lucide: ['plus', 'book-open', 'zap', 'cpu', 'activity', 'circuit-board', 'file-text', 'chevron-down', 'arrow-right', 'check-circle-2'] } }),
   ],
   telemetry: false,
   devToolbar: { enabled: false },