T-MATH-RENDER: proper LaTeX/math rendering in Glossary + Recipes panels

[EYH0602]

Summary

Render inline/display LaTeX (e.g. $\pi^{(k)}$, $\Phi^{k;s}$, aligned equations) in the Concepts (Glossary) and Solution (Recipes) panels with a KaTeX-style renderer, replacing the v1 inert-monospace fallback.

Background

logic/concepts.md and logic/solution/*.md in the real corpus carry heavy math (notation blocks, multi-step derivations). The hub-parity work (plans/hub-parity-full.md, decision D3) deliberately ships inert monospace $…$ for v1:

• honest (fakes nothing), cheap, and keeps the enforced sub-MB wasm bundle gate green;
• but unreadable for real equations.

This issue tracks the follow-up: make the math legible.

Why deferred

A KaTeX/MathML renderer adds JS/wasm weight that tensions the sub-MB bundle gate, and is not needed for structural parity with the hub. Ship structure first, add math typesetting after.

Approach to evaluate

• A wasm-safe pure-Rust math typesetter, or
• a lazily-loaded KaTeX bundle (kept out of the main wasm bundle so the size gate stays green).

Depends on

• The Glossary/Recipes panels shipping (hub-parity slice 5).

Tracked in TODOS.md as T-MATH-RENDER.