:gem: [Feature] More widgets of agent info sidebar

:gem: [Feature] Replace top select from available models to agents, and auto set default agent

:zap: [Enhance] Prettify styles of agent buttons

:zap: [Enhance] Switch dark mode with darkreader.js

:zap: [Enhance] Enable RangeNumber widget append and real-time update, generalize widget_id, and check existance before creating modal

:zap: [Enhance] Prettify form formats of new agent modal, and auto resize system prompt input

:hammer: [WIP] NewAgentModal: Prettify with form-floating; need to auto height

:hammer: [WIP] New Agent Modal: Enable toggle button and prototype

:zap: [Enhance] New Agent button placeholder

:zap: [Enhance] Prettify dark theme

:gem: [Feature] New dark theme toggle button

:gem: [Feature] New Chat Agents Sidebar

:zap: [Enhance] Correctly place components in main-container with d-flex css

:recycle: [Refactor] Re-position styles in css

:zap: [Enhance] Finetune margin and padding of messagers-container for screenshot

:zap: [Enhance] css for top-toolbar, and re-position styles for fa

:zap: [Enhance] Replace background from gradient image to color to adaptive dark theme

:zap: [Enhance] Replace some bootstrap styles with pure css, and improve color palettes

:zap: [Enhance] Prettify UI by adding box-shadow and background-image linear-gradient

:gem: [Feature] Responsive and adaptive chat-history-sidebar

:zap: [Enhance] Do not render user input, and keep line breaks

:zap: [Enhance] Background color when inferring

:zap: [Enhance] Softer effects for blinking

:zap: [Enhance] Displayer: Prettify button-group

:recycle: [Refactor] Move default.css to css dir