feat(chat): redesign chat and add theme support

[BrunoQuaresma]

What is done:

• Redesign chat
• Add support for light and dark themes
• Use shadcn/ui

Before:

Light:

Dark:

[hugodutka]

Love the new design! I spotted a couple of minor issues:

1. The text returned by the api must use a mono font and exactly 80 columns to render correctly - that's the width of the underlying virtual terminal.

2. Key tiles overlap in control mode.

Screen.Recording.2025-05-20.at.10.19.46.mov

3. Instead of displaying three dots for the user message while it's being sent maybe let's optimistically display the user message itself and move the three dots to the agent side?

Screen.Recording.2025-05-20.at.10.21.28.mov

4. Could we pin the message box to the bottom of the page? I think that's how most AI chat interfaces do it.

5. Loading dots for agent messages look a little off, like there's too little padding on them or maybe they are too small. You can see it for example with OpenAI Codex (OPENAI_API_KEY=xxx go run main.go server -- codex)

Screen.Recording.2025-05-20.at.10.36.27.mov

[BrunoQuaresma]

1. The text returned by the api must use a mono font and exactly 80 columns to render correctly - that's the width of the underlying virtual terminal.

It is using Geist Mono as mono font. What do you mean by "exactly 80 columns"? Does it mean, 80 letters?

2. Key tiles overlap in control mode.

Good catch!

3. Instead of displaying three dots for the user message while it's being sent maybe let's optimistically display the user message itself and move the three dots to the agent side?

Yes!

4. Could we pin the message box to the bottom of the page? I think that's how most AI chat interfaces do it.

It should be pinned already. Let me fix that.

5. Loading dots for agent messages look a little off, like there's too little padding on them or maybe they are too small. You can see it for example with OpenAI Codex (OPENAI_API_KEY=xxx go run main.go server -- codex)

Lets make it bigger!

[hugodutka]

looks great! ship it