Add initial infrastructure and backup scripts for Gitea and homelab deployment

- Create README.md with project layout and quick start instructions
- Implement backup scripts for Gitea, including database and repository exports
- Add systemd service and timer for automated Gitea backups
- Develop bootstrap scripts for homelab and VPS setup
- Document architecture and restore procedures
- Configure Caddy reverse proxy and Docker Compose for service management
- Establish secrets management guidelines

secrets/README.md

@@ -0,0 +1,15 @@
+# Secrets
+
+Do not commit plaintext secrets.
+
+## Pattern
+
+- Commit encrypted blobs only (`*.age`).
+- Decrypt to `/srv/secrets/*` at bootstrap/runtime.
+- Keep private decryption key outside git.
+
+## Expected encrypted files
+
+- `tailscale_authkey.age`
+- `gitea_token.age` (optional)
+- `postgres_password.age` (optional)