feat: portfolio redesign with i18n, RBC project showcase, CI/CD

- Add i18n support (EN/ZH) with language toggle
- Redesign header with education dropdown, contact copy buttons
- Add RBC project showcase with bullet points, skills highlighting
- Create terraform-drift placeholder page
- Add ProjectShowcase component with media toggle (image/video)
- Update experience timeline with action-driven descriptions
- Add Docker + Forgejo CI workflow for image builds
- Update K8s manifests for riotpiao.com ingress
- Add DESIGN.md documenting design system patterns

infra/portfolio/base/deployment.yaml

@@ -18,7 +18,7 @@ spec:
     spec:
       containers:
       - name: portfolio
-        image: forgejo.riotpiao.homelab.com/rock/portfolio:latest
+        image: forgejo.riotpiao.com/rock/portfolio:latest
         imagePullPolicy: IfNotPresent
         ports:
         - name: http