docs: add MarkoTalk callouts to README, introduction, and chat tutorial

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: markshust

README.md

@@ -321,6 +321,12 @@ Marko ships as composable packages — require only what you need. Every package
 |---------|-------------|
 | [testing](packages/testing/README.md) | Test fakes, assertions, and Pest expectations |
 
+## Example Applications
+
+| App | Description |
+|-----|-------------|
+| [MarkoTalk](https://github.com/marko-php/markotalk) | Real-time community chat — dogfoods plugins, preferences, events, SSE, and the admin panel |
+
 ## Requirements
 
 - PHP 8.5+

docs/src/content/docs/getting-started/introduction.md

@@ -48,6 +48,10 @@ marko/cache-redis    → RedisCacheDriver (Redis implementation)
 
 You code against the interface. Swap implementations by changing a single binding — no other code changes needed.
 
+## See It in Action
+
+[MarkoTalk](https://github.com/marko-php/markotalk) is a real-time community chat app built with Marko. It dogfoods the framework's module system, plugins, preferences, events, SSE, and admin panel in a production-quality application. It's the best way to see how everything fits together.
+
 ## What's Next?
 
 - [Install Marko](/docs/getting-started/installation/) and create your first project

docs/src/content/docs/tutorials/build-a-chat.md

@@ -448,7 +448,7 @@ The replay loop creates `SseEvent` objects with explicit `id` values. When the b
 marko up
 ```
 
-`marko up` (alias for `dev:up`) starts the full development environment automatically --- PHP server, Docker if detected, pub/sub listener if pubsub packages are installed, and frontend build tools if detected. For SSE applications this is important: `marko up` starts PHP with `PHP_CLI_SERVER_WORKERS=4` by default, so the SSE connection does not block all other requests on the single-threaded PHP built-in server. MarkoTalk (the reference chat implementation) uses this same approach.
+`marko up` (alias for `dev:up`) starts the full development environment automatically --- PHP server, Docker if detected, pub/sub listener if pubsub packages are installed, and frontend build tools if detected. For SSE applications this is important: `marko up` starts PHP with `PHP_CLI_SERVER_WORKERS=4` by default, so the SSE connection does not block all other requests on the single-threaded PHP built-in server. [MarkoTalk](https://github.com/marko-php/markotalk) (the reference chat implementation) uses this same approach.
 
 In separate terminals, test the flow: