feat: SPA routing, projects/resume sections, deployment infra

- Add client-side router with History API pushState (router.ts, pages.ts)
- Extend overlay with projects grid/category/detail views and resume section
- Add Gitea CI/CD workflow and webhook deployment server
- Improve Docker Compose with nginx reverse proxy config
- Add deployment script and .env.example

webhook/webhook.service

@@ -0,0 +1,24 @@
+[Unit]
+Description=WebGPU Portfolio webhook receiver
+After=network.target docker.service
+Requires=docker.service
+
+[Service]
+Type=simple
+User=djoser
+WorkingDirectory=/home/djoser/webgpu-portfolio
+EnvironmentFile=/home/djoser/webgpu-portfolio/.env
+ExecStart=/usr/bin/python3 /home/djoser/webgpu-portfolio/webhook/server.py
+Restart=always
+RestartSec=5
+
+# Security hardening
+NoNewPrivileges=yes
+PrivateTmp=yes
+ProtectSystem=strict
+ProtectHome=read-only
+ReadWritePaths=/home/djoser/webgpu-portfolio
+ReadOnlyPaths=/var/run/docker.sock
+
+[Install]
+WantedBy=multi-user.target