chore: replace OSS weekend with permanent contribution gate

.github/ISSUE_TEMPLATE/bug.yml

@@ -2,6 +2,15 @@ name: Bug Report
 description: Report something that's broken
 labels: ["bug"]
 body:
+  - type: markdown
+    attributes:
+      value: |
+        **Before you start:** Read [CONTRIBUTING.md](https://github.com/badlogic/pi-mono/blob/main/CONTRIBUTING.md).
+
+        New issues from new contributors are auto-closed by default. Maintainers review auto-closed issues daily. Issues that do not meet the quality bar in [CONTRIBUTING.md](https://github.com/badlogic/pi-mono/blob/main/CONTRIBUTING.md) will not be reopened or receive a reply.
+
+        Keep this short. If it doesn't fit on one screen, it's too long. Write in your own voice.
+
   - type: textarea
     id: description
     attributes: