fix: SSE keepalive via plugin-kit 0.1.4 (v0.3.1)

Live-verified against a running host: status frames (including a syncing
transition) now stream through the plugin UI server. The previous keepalive
outlived Bun's default idle timeout, so an idle feed was closed before its
first ping.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

contract/package.json

@@ -14,11 +14,11 @@
 	},
 	"peerDependencies": {
 		"effect": "^4.0.0-beta.99",
-		"@punktfunk/plugin-kit": "^0.1.3"
+		"@punktfunk/plugin-kit": "^0.1.4"
 	},
 	"devDependencies": {
 		"effect": "4.0.0-beta.99",
-		"@punktfunk/plugin-kit": "^0.1.3",
+		"@punktfunk/plugin-kit": "^0.1.4",
 		"typescript": "^5.9.3",
 		"@types/bun": "^1.3.0"
 	}