Add Gitea CI/CD workflow for Cloudflare Pages deployment

- Add deploy.yaml workflow triggered on prod branch push
- Add push:prod script for convenience

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

package.json

@@ -11,7 +11,8 @@
 		"check": "svelte-kit sync && svelte-check --tsconfig ./tsconfig.json",
 		"check:watch": "svelte-kit sync && svelte-check --tsconfig ./tsconfig.json --watch",
 		"lint": "prettier --check . && eslint .",
-		"format": "prettier --write ."
+		"format": "prettier --write .",
+		"push:prod": "git push origin main:prod"
 	},
 	"devDependencies": {
 		"@eslint/compat": "^2.0.4",