feat(logs): Add inline JSON syntax highlighting for log attributes

When a log attribute value contains embedded JSON within surrounding
text (e.g. "This is my JSON: {"key": "value"}"), the JSON portions
are now syntax-highlighted inline using Prism tokenization while the
non-JSON text renders as-is.

This builds on the existing full-JSON pretty-printing from LOGS-400.
The JSON extraction logic is in a standalone, dependency-free utility
(extractJsonFromText) with string-aware bracket matching that correctly
handles braces inside quoted strings and escape sequences.

Refs LINEAR-LOGS-636

Co-Authored-By: Claude Sonnet 4 <noreply@anthropic.com>
Made-with: Cursor

Author: JoshuaKGoldberg