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/ingress.yaml

@@ -3,16 +3,13 @@ kind: Ingress
 metadata:
   name: portfolio
   namespace: portfolio
-  annotations:
-    cert-manager.io/cluster-issuer: letsencrypt-prod
 spec:
-  ingressClassName: nginx
   tls:
   - hosts:
-    - portfolio.riotpiao.homelab.com
+    - riotpiao.com
     secretName: portfolio-tls
   rules:
-  - host: portfolio.riotpiao.homelab.com
+  - host: riotpiao.com
     http:
       paths:
       - path: /