ci: add self-hosted Renovate for cross-repo dependency sync

Scheduled Renovate bot (renovate.yml) + shared preset (renovate-config.json)
that every game/plaza repo extends, so dependency bumps land the same way
across repos. @played/* grouped together, third-party non-major batched.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

renovate-config.json

@@ -0,0 +1,24 @@
+{
+	"$schema": "https://docs.renovatebot.com/renovate-schema.json",
+	"extends": ["config:recommended", ":dependencyDashboard", ":semanticCommits"],
+	"timezone": "Europe/Berlin",
+	"rangeStrategy": "bump",
+	"labels": ["dependencies"],
+	"packageRules": [
+		{
+			"description": "Bump the internal @played/* packages together, promptly.",
+			"matchPackageNames": ["/^@played//"],
+			"groupName": "@played packages"
+		},
+		{
+			"description": "Batch third-party non-major updates into one PR to cut noise.",
+			"matchUpdateTypes": ["minor", "patch"],
+			"matchPackageNames": ["!/^@played//"],
+			"groupName": "non-major dependencies"
+		}
+	],
+	"lockFileMaintenance": {
+		"enabled": true,
+		"schedule": ["before 9am on monday"]
+	}
+}