server : (webui) revamp the input area, plus many small UI improvements (#13365)

* rework the input area

* process selected file

* change all icons to heroicons

* fix thought process collapse

* move conversation more menu to sidebar

* sun icon --> moon icon

* rm default system message

* stricter upload file check, only allow image if server has mtmd

* build it

* add renaming

* better autoscroll

* build

* add conversation group

* fix scroll

* extra context first, then user input in the end

* fix <hr> tag

* clean up a bit

* build

* add mb-3 for <pre>

* throttle adjustTextareaHeight to make it less laggy

* (nits) missing padding in sidebar

* rm stray console log

tools/server/webui/vite.config.ts

@@ -71,6 +71,7 @@ export default defineConfig({
   server: {
     proxy: {
       '/v1': 'http://localhost:8080',
+      '/props': 'http://localhost:8080',
     },
     headers: {
       'Cross-Origin-Embedder-Policy': 'require-corp',