feat(run/chat): add Markdown rendering

[doringeman]

To try it locally, checkout this branch and run:

make install

E.g.,

In the second commit I added a --color flag to choose whether you want the output to be colored and formatted:

Options:
      --color string                  Use colored output (auto|yes|no) (default "auto")

I decided to also display the token usage:

[ericcurtin]

In the CLI case, we may not want to blindly add color/md, we should check that the terminal supports color, that we are not redirecting to a file, etc. Because in these cases you want to use plain-old text, an example of how you do this is here:

ggml-org/llama.cpp#15792 (common_log_should_use_colors_auto function)

grep, systemd, ramalama would be other reference implementations of this.

[Copilot]

Pull Request Overview

This PR adds Markdown rendering functionality to the chat feature, replacing the previous text output with styled Markdown rendering using the glamour library.

• Removes the fatih/color dependency and replaces it with charmbracelet/glamour for Markdown rendering
• Refactors the Chat method to return response content instead of directly printing to stdout
• Adds terminal-aware Markdown rendering with automatic width detection and fallback to plain text

Reviewed Changes

Copilot reviewed 4 out of 783 changed files in this pull request and generated 1 comment.

File	Description
go.mod	Adds glamour and related dependencies, removes fatih/color dependency
desktop/desktop.go	Refactors Chat method to return response content and removes direct console output
desktop/desktop_test.go	Updates test to handle Chat method's new return signature
commands/run.go	Adds Markdown rendering functionality with terminal width detection and fallback handling

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[Copilot]

Global variables markdownRenderer and lastWidth are not thread-safe. If multiple goroutines call getMarkdownRenderer() concurrently, this could lead to race conditions when checking and updating these variables.

[doringeman]

In the CLI case, we may not want to blindly add color/md, we should check that the terminal supports color, that we are not redirecting to a file, etc. Because in these cases you want to use plain-old text, an example of how you do this is here:

ggml-org/llama.cpp#15792 (common_log_should_use_colors_auto function)

grep, systemd, ramalama would be other reference implementations of this.

Good point. Thanks!
Moreover, I was thinking of also adding a --disable-markdown flag to disable the formatting. WDYT?

[ericcurtin]

In the CLI case, we may not want to blindly add color/md, we should check that the terminal supports color, that we are not redirecting to a file, etc. Because in these cases you want to use plain-old text, an example of how you do this is here:
ggml-org/llama.cpp#15792 (common_log_should_use_colors_auto function)
grep, systemd, ramalama would be other reference implementations of this.

Good point. Thanks! Moreover, I was thinking of also adding a --disable-markdown flag to disable the formatting. WDYT?

If it was me, I would do both like llama-server/grep does:

--color [auto|yes|no]

with auto being the default.

I do wonder about markdown for the CLI in general, that makes sense to me for the UI, but for CLI, people may not want that. Syntax highlighting I think makes sense though for code blocks etc.

If you want --color and --markdown to be one combined flag or separate flags, I'll let you make that choice but I suggest making it a flag with 3 options with auto being the default:

[on|off|auto] 

[xenoscopic]

I also think auto is the right default here. The criteria that github.com/fatih/color uses are probably the most battle tested for Go:

https://github.com/fatih/color/blob/1c8d8706604ee5fb9a464e5097ba113101828a75/color.go#L16-L23

You could either add it back as a dependency (I'm sure we can find other uses) and use its NoColor variable or emulate the same rules. I don't see anything automatic in glamour.

[ericcurtin]

I also think auto is the right default here. The criteria that github.com/fatih/color uses are probably the most battle tested for Go:

https://github.com/fatih/color/blob/1c8d8706604ee5fb9a464e5097ba113101828a75/color.go#L16-L23

You could either add it back as a dependency (I'm sure we can find other uses) and use its NoColor variable or emulate the same rules. I don't see anything automatic in glamour.

Yup, that's super similar to what we did in llama-server

[doringeman]

This breaks the streaming experience. I need to come up with a solution to keep streaming the text and only block for a bit while, for example, a Markdown code block is completed.