Store ChromaHighlighter in lmcli.Context and use it

In preparation for TUI

pkg/lmcli/lmcli.go

@@ -8,6 +8,7 @@ import (
 	"git.mlow.ca/mlow/lmcli/pkg/lmcli/provider"
 	"git.mlow.ca/mlow/lmcli/pkg/lmcli/provider/anthropic"
 	"git.mlow.ca/mlow/lmcli/pkg/lmcli/provider/openai"
+	"git.mlow.ca/mlow/lmcli/pkg/util/tty"
 	"gorm.io/driver/sqlite"
 	"gorm.io/gorm"
 )
@@ -15,6 +16,8 @@ import (
 type Context struct {
 	Config Config
 	Store  ConversationStore
+
+	Chroma *tty.ChromaHighlighter
 }
 
 func NewContext() (*Context, error) {
@@ -34,7 +37,9 @@ func NewContext() (*Context, error) {
 		Fatal("%v\n", err)
 	}
 
-	return &Context{*config, s}, nil
+	hl := tty.NewChromaHighlighter("markdown", *config.Chroma.Formatter, *config.Chroma.Style)
+
+	return &Context{*config, s, hl}, nil
 }
 
 func (c *Context) GetCompletionProvider(model string) (provider.ChatCompletionClient, error) {