feat(FR-434): support math in model card.

[agatha197]

resolves #3066 (FR-434 / parent: FR-432)

Adds LaTeX math formula support to chat messages using KaTeX. This enables rendering of mathematical equations and expressions within markdown content.

Changes:

• Added remark-math and rehype-katex plugins to markdown renderer
• Updated react-markdown to version 9.0.3
• Integrated KaTeX dependencies for math formula processing

How to test:
Use deepseek model in dogbowl.

Checklist:

• Documentation
• Test case(s) to demonstrate the difference of before/after

[agatha197]

• feat(FR-433): wrap customTags contents with Collapse #3073
• feat(FR-434): support math in model card. #3067 👈 (View in Graphite)
• main

---

How to use the Graphite Merge Queue

Add either label to this PR to merge it via the merge queue:

• flow:merge-queue - adds this PR to the back of the merge queue
• flow:hotfix - for urgent hot fixes, skip the queue and merge this PR next

You must have a Graphite account in order to use the merge queue. Sign up using this link.

An organization admin has required the Graphite Merge Queue in this repository.

Please do not merge from GitHub as this will restart CI on PRs being processed by the merge queue.

This stack of pull requests is managed by Graphite. Learn more about stacking.

[github-actions]

Coverage report for ./react

St.❔	Category	Percentage	Covered / Total
🔴	Statements	4.92%	398/8093
🔴	Branches	4.25%	239/5629
🔴	Functions	2.95%	78/2641
🔴	Lines	4.84%	383/7918

Test suite run success

124 tests passing in 14 suites.

Report generated by 🧪jest coverage report action from fc8b122