CACHE-11939: add request cf overriding cache rules compat flags

Author: Yawar Jamal

src/content/compatibility-flags/fetch-api-request-cf-overrides-cache-rules.md

@@ -0,0 +1,16 @@
+---
+_build:
+  publishResources: false
+  render: never
+  list: never
+
+name: "Override cache rules cache settings in `request.cf` object for Fetch API"
+sort_date: "2023-08-01"
+enable_date: "2025-04-02"
+enable_flag: "request_cf_overrides_cache_rules"
+disable_flag: "no_request_cf_overrides_cache_rules"
+---
+
+This flag fixes the behavior of cache when requesting assets via the Fetch API whereby the cache settings specified in the `request.cf` object is given precedence over any Cache Rules set. 
+
+With the flag enabled - either by default after 2025-03-26 or by setting the `request_cf_overrides_cache_rules` flag - any cache related settings in a Worker's `request.cf` object such as (`cacheEverything`, `cacheTtl`, etc) will override any cache rules for the target asset in subrequest.