restore install snippet on Create, broaden computer-use vs playwright copy

- Add the SDK install Info block back to Create (was on the old
  browsers/create-a-browser page).
- Anchor the termination link to the automatic-deletion section.
- Rewrite the "Computer use + playwright execution" intro: computer
  controls don't just lack DOM reads, they lack the whole programmatic
  surface (page.goto, file uploads, cookies, tab switching). Reach for
  playwright execution whenever you need any of that.

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

Author: masnwilliams

introduction/control.mdx

@@ -161,7 +161,7 @@ If you're reaching for Playwright, prefer the execution API over `connectOverCDP
 
 ## Computer use + playwright execution
 
-The one thing computer controls don't do natively: read the DOM. The recommended pattern for agents is computer controls for interaction, [playwright execution](/browsers/playwright-execution) as a DOM-reading tool when the agent needs structured data.
+Computer controls drive the browser the way a person would — they don't speak the programmatic API surface. Anything you'd reach for the DOM or Playwright client for (reading text and attributes, `page.goto`, file uploads, cookie or storage access, switching tabs) belongs on the [playwright execution](/browsers/playwright-execution) side. The recommended pattern for agents is computer controls for interaction, playwright execution as a tool the agent can call when it needs structured data or a programmatic action.
 
 <CodeGroup>
 ```typescript Typescript/Javascript

introduction/create.mdx

@@ -7,6 +7,12 @@ Kernel browsers are sandboxed Chromium instances that boot in under 30ms. Your a
 
 ## Your first browser
 
+<Info>
+  Install the Kernel SDK first:
+  - Typescript/Javascript: `npm install @onkernel/sdk`
+  - Python: `pip install kernel`
+</Info>
+
 <CodeGroup>
 ```typescript Typescript/Javascript
 import Kernel from '@onkernel/sdk';
@@ -75,7 +81,7 @@ kernel browsers delete <session-id>
 ```
 </CodeGroup>
 
-See [Termination & timeouts](/browsers/termination) for the full set of teardown options.
+See [Termination & timeouts](/browsers/termination#automatic-deletion-via-timeout) for the full set of teardown options.
 
 ## Full example