server: (UI) add syntax highlighting and latex math rendering (#10808)

* add code highlighting and math formatting

* code cleanup

* build public/index.html

* rebuild public/index.html

* fixed coding style

* fixed coding style

* style fixes

* highlight: smaller bundle size, fix light & dark theme

* remove katex

* add bundle size check

* add more languages

* add php

* reuse some langs

* use gzip

* Revert "remove katex"

This reverts commit c0e5046.

* use better maintained @vscode/markdown-it-katex

* fix gzip non deterministic

* ability to add a demo conversation for dev

* fix latex rendering

* add comment

* latex codeblock as code

---------

Co-authored-by: Xuan Son Nguyen <[email protected]>

Author: VJHack

examples/server/CMakeLists.txt

@@ -15,7 +15,7 @@ set(TARGET_SRCS
     httplib.h
 )
 set(PUBLIC_ASSETS
-    index.html
+    index.html.gz
     loading.html
 )
 

examples/server/public/index.html

@@ -15,7 +15,7 @@
 #define MIMETYPE_JSON "application/json; charset=utf-8"
 
 // auto generated files (update with ./deps.sh)
-#include "index.html.hpp"
+#include "index.html.gz.hpp"
 #include "loading.html.hpp"
 
 #include <atomic>
@@ -3828,8 +3828,13 @@ int main(int argc, char ** argv) {
             }
         } else {
             // using embedded static index.html
-            svr->Get("/", [](const httplib::Request &, httplib::Response & res) {
-                res.set_content(reinterpret_cast<const char*>(index_html), index_html_len, "text/html; charset=utf-8");
+            svr->Get("/", [](const httplib::Request & req, httplib::Response & res) {
+                if (req.get_header_value("Accept-Encoding").find("gzip") == std::string::npos) {
+                    res.set_content("Error: gzip is not supported by this browser", "text/plain");
+                } else {
+                    res.set_header("Content-Encoding", "gzip");
+                    res.set_content(reinterpret_cast<const char*>(index_html_gz), index_html_gz_len, "text/html; charset=utf-8");
+                }
                 return false;
             });
         }

examples/server/public/index.html.gz

@@ -201,6 +201,10 @@ <h3 class="text-lg font-bold mb-6">Settings</h3>
           <details class="collapse collapse-arrow bg-base-200 mb-2 overflow-visible">
             <summary class="collapse-title font-bold">Advanced config</summary>
             <div class="collapse-content">
+              <div class="flex flex-row items-center mb-2" v-if="isDev">
+                <!-- this button only shows in dev mode, used to import a demo conversation to test message rendering -->
+                <button class="btn" @click="debugImportDemoConv()">(debug) Import demo conversation</button>
+              </div>
               <div class="flex flex-row items-center mb-2">
                 <input type="checkbox" class="checkbox" v-model="config.showTokensPerSecond" />
                 <span class="ml-4">Show tokens per second</span>