Implement interactive CLI for LLM providers with chat, tools, and image support

- Add Bubble Tea-based CLI interface for LLM interactions.
- Implement `.env.example` for environment variable setup.
- Add provider, model, and tool selection screens.
- Include support for API key configuration.
- Enable chat interactions with optional image and tool support.
- Introduce core utility functions: image handling, tool execution, chat request management, and response rendering.
- Implement style customization with Lip Gloss.

cmd/llm/styles.go

@@ -0,0 +1,113 @@
+package main
+
+import (
+	"github.com/charmbracelet/lipgloss"
+)
+
+var (
+	// Colors
+	primaryColor   = lipgloss.Color("205")
+	secondaryColor = lipgloss.Color("39")
+	accentColor    = lipgloss.Color("212")
+	mutedColor     = lipgloss.Color("241")
+	errorColor     = lipgloss.Color("196")
+	successColor   = lipgloss.Color("82")
+
+	// App styles
+	appStyle = lipgloss.NewStyle().Padding(1, 2)
+
+	// Header
+	headerStyle = lipgloss.NewStyle().
+			Bold(true).
+			Foreground(primaryColor).
+			BorderStyle(lipgloss.NormalBorder()).
+			BorderBottom(true).
+			BorderForeground(mutedColor).
+			Padding(0, 1)
+
+	// Provider badge
+	providerBadgeStyle = lipgloss.NewStyle().
+				Background(secondaryColor).
+				Foreground(lipgloss.Color("0")).
+				Padding(0, 1).
+				Bold(true)
+
+	// Messages
+	systemMsgStyle = lipgloss.NewStyle().
+			Foreground(mutedColor).
+			Italic(true).
+			Padding(0, 1)
+
+	userMsgStyle = lipgloss.NewStyle().
+			Foreground(secondaryColor).
+			Padding(0, 1)
+
+	assistantMsgStyle = lipgloss.NewStyle().
+				Foreground(lipgloss.Color("255")).
+				Padding(0, 1)
+
+	roleLabelStyle = lipgloss.NewStyle().
+			Bold(true).
+			Width(12)
+
+	// Tool calls
+	toolCallStyle = lipgloss.NewStyle().
+			Foreground(accentColor).
+			Italic(true).
+			Padding(0, 1)
+
+	toolResultStyle = lipgloss.NewStyle().
+			Foreground(successColor).
+			Padding(0, 1)
+
+	// Input area
+	inputStyle = lipgloss.NewStyle().
+			BorderStyle(lipgloss.RoundedBorder()).
+			BorderForeground(primaryColor).
+			Padding(0, 1)
+
+	inputHelpStyle = lipgloss.NewStyle().
+			Foreground(mutedColor).
+			Italic(true)
+
+	// Error
+	errorStyle = lipgloss.NewStyle().
+			Foreground(errorColor).
+			Bold(true)
+
+	// Loading
+	loadingStyle = lipgloss.NewStyle().
+			Foreground(accentColor).
+			Italic(true)
+
+	// List selection
+	selectedItemStyle = lipgloss.NewStyle().
+				Foreground(primaryColor).
+				Bold(true)
+
+	normalItemStyle = lipgloss.NewStyle().
+			Foreground(lipgloss.Color("255"))
+
+	// Settings panel
+	settingLabelStyle = lipgloss.NewStyle().
+				Foreground(secondaryColor).
+				Width(15)
+
+	settingValueStyle = lipgloss.NewStyle().
+				Foreground(lipgloss.Color("255"))
+
+	// Help text
+	helpStyle = lipgloss.NewStyle().
+			Foreground(mutedColor).
+			Padding(1, 0)
+
+	// Image indicator
+	imageIndicatorStyle = lipgloss.NewStyle().
+				Foreground(accentColor).
+				Bold(true)
+
+	// Viewport
+	viewportStyle = lipgloss.NewStyle().
+			BorderStyle(lipgloss.NormalBorder()).
+			BorderForeground(mutedColor)
+)