chore: add htmx.min.js and update gitignore for doc dependencies

- Added htmx.min.js to git (previously only downloaded during build)
- Updated .gitignore to explicitly allow documentation dependencies
- Clarified compiled vs downloaded JS in gitignore comments

.gitignore

@@ -17,8 +17,17 @@ package-lock.json
 *.d.ts.map
 
 # Compiled JavaScript (keep .ts source, ignore .js)
+# Exception: Downloaded documentation dependencies
+web/static/compiled-*.js
 web/static/*.js
 
+# Downloaded documentation dependencies (tracked in git)
+!web/static/htmx.min.js
+!web/static/highlight.min.js
+!web/static/highlight-dark.min.css
+!web/static/lunr.min.js
+!web/static/lunr-flex.min.js
+
 # Temporary files
 tmp/
 temp/