Add Typst export with color variable definitions

Implements Typst export functionality using the tex2typst library for
LaTeX-to-Typst conversion. Defines colors as variables at the top of
the document and references them throughout, following best practices:

// Color definitions
#let termexponential = rgb("#e6194B")
#let termimaginary = rgb("#3cb44b")
...

// Referenced in equation and text
$ #text(fill: termexponential)[$e$]^... $

The tex2typst library (v0.4.1) was chosen after testing because it
natively handles \textcolor commands and converts them to proper
Typst syntax. The implementation:

1. Preprocesses \htmlClass{term-X}{content} to \textcolor{#hex}{content}
2. Converts LaTeX to Typst using tex2typst
3. Post-processes to replace inline rgb() calls with variable references

Adds Typst export button to the UI export menu.

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

Co-Authored-By: Claude <[email protected]>

Author: stared

index.html

@@ -64,6 +64,7 @@ <h1 id="equation-title">Interactive Equations</h1>
               <button class="export-option" data-format="html">HTML</button>
               <button class="export-option" data-format="latex">LaTeX</button>
               <button class="export-option" data-format="beamer">Beamer</button>
+              <button class="export-option" data-format="typst">Typst</button>
             </div>
           </div>
           <button id="copy-btn" class="toolbar-btn" title="Copy to clipboard">Copy</button>

package.json

@@ -37,6 +37,8 @@
   "dependencies": {
     "codejar": "^4.3.0",
     "katex": "^0.16.25",
-    "prismjs": "^1.30.0"
+    "prismjs": "^1.30.0",
+    "tex-to-typst": "^0.0.19",
+    "tex2typst": "^0.4.1"
   }
 }