docs(audience): promote testMode note to its own section in READMEs

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

Author: bkbooth

packages/audience/pixel/README.md

@@ -152,7 +152,17 @@ Note: the nonce covers the inline snippet only. The CDN-loaded script (`imtbl.js
 | Safari | 14+ |
 | Edge | 80+ |
 
-Pass `"testMode": true` in the init options to mark all events with `test: true`, which lets you filter test traffic from production analytics.
+## Test mode
+
+Set `"testMode": true` in the init options to mark every event with a
+top-level `test: true` flag. Useful for development, staging, or QA —
+events still flow through the production endpoint, but can be filtered
+out of production analytics downstream.
+
+```diff
+- w[i].push(["init",{"key":"YOUR_KEY","consent":"anonymous"}]);
++ w[i].push(["init",{"key":"YOUR_KEY","consent":"anonymous","testMode":true}]);
+```
 
 ## Documentation
 

packages/audience/sdk/README.md

@@ -61,7 +61,19 @@ audience.shutdown();
 </script>
 ```
 
-Pass `testMode: true` in the config to mark all events with `test: true`, which lets you filter test traffic from production analytics.
+## Test mode
+
+Pass `testMode: true` in the config to mark every event with a top-level
+`test: true` flag. Useful for development, staging, or QA — events still
+flow through the production endpoint, but can be filtered out of
+production analytics downstream.
+
+```ts
+Audience.init({
+  publishableKey: 'YOUR_PUBLISHABLE_KEY',
+  testMode: true,
+});
+```
 
 ## Documentation