feat: cloudflare cache guide

deployment/cloudflare-cache-rules.md

@@ -0,0 +1,20 @@
+# Cloudflare Configuration
+
+To optimize performance, configure Cloudflare to offload traffic from your server. We use **Cache Rules** to cache public stream results while respecting the application's cache headers.
+
+## 1. Public Streams (Cache Rule)
+Allow Cloudflare to cache public stream results. Comet automatically controls the duration (TTL) and freshness (Stale-While-Revalidate) via headers.
+
+*   **Rule Name**: Public Streams
+*   **Expression**: `(starts_with(http.request.uri.path, "/stream/"))`
+*   **Action**: Eligible for Cache
+*   **Edge TTL**: Use cache-control header if present
+*   **Browser TTL**: Respect origin
+*   **Serve stale content while revalidating**: On
+
+## 2. Tiered Cache
+Enable **Tiered Cache** in **Caching > Tiered Cache**.
+This minimizes requests to your origin by checking other Cloudflare datacenters first.
+
+---
+*Note: Private streams (URLs containing your configuration) are automatically excluded because they do not start with `/stream/`.*