feat(nextjs): Improve logs documentation with split-view layout (#15919)

## Summary

Redesigns the Next.js Logs documentation with improved layout and
content:

- **Split-view layout** — Text explanations on left, code examples on
right
- **Inlined integrations** — Console, Pino, Consola, Winston with
split-view
- **Sample payload** — Shows all default attributes in context (replaces
verbose tables)
- **Troubleshooting section** — Common issues: enableLogs config,
dropped logs, filtered data
- **Best practices** — Wide events, business context, consistent naming

## Why Next.js-specific?

Next.js requires `enableLogs: true` in **3 separate config files**
(client, server, edge), unlike most SDKs that have a single init.

## Future work

This split-view layout can be applied to other SDK logs docs. The
pattern established here (setup, usage, integrations, best practices,
troubleshooting) can become the standard template.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Opus 4.5 <[email protected]>

Author: 2 people

docs/platforms/javascript/guides/nextjs/index.mdx

@@ -112,6 +112,9 @@ Sentry.init({
   // ___PRODUCT_OPTION_START___ performance
   tracesSampleRate: process.env.NODE_ENV === "development" ? 1.0 : 0.1,
   // ___PRODUCT_OPTION_END___ performance
+  // ___PRODUCT_OPTION_START___ logs
+  enableLogs: true,
+  // ___PRODUCT_OPTION_END___ logs
 });
 ```