feat: upgrade to lipgloss v2 (#94)

Hi! 

I upgraded lipgloss to v2 and also took the opportunity to migrate some
of the raw escape sequence handling to x/ansi. Feel free to cherry pick
whatever is helpful from this!

integration/overlay.go

@@ -2,12 +2,14 @@ package integration
 
 import (
 	"fmt"
+	"image/color"
 	"os"
 	"strconv"
 	"strings"
 	"sync"
 	"unicode/utf8"
-	"github.com/charmbracelet/lipgloss"
+
+	"charm.land/lipgloss/v2"
 	"github.com/versenilvis/iris/internal/config"
 	"github.com/versenilvis/iris/internal/logger"
 	"github.com/versenilvis/iris/spec"
@@ -127,17 +129,17 @@ func ComputeCursorCol(data []byte) int {
 }
 
 type Theme struct {
-	Border     lipgloss.Color
-	Accent     lipgloss.Color
-	Muted      lipgloss.Color
-	Text       lipgloss.Color
-	TextSel    lipgloss.Color
-	Match      lipgloss.Color
-	Desc       lipgloss.Color
-	DescSel    lipgloss.Color
-	SelBg      lipgloss.Color
-	ScrollInfo lipgloss.Color
-	GhostText  lipgloss.Color
+	Border     color.Color
+	Accent     color.Color
+	Muted      color.Color
+	Text       color.Color
+	TextSel    color.Color
+	Match      color.Color
+	Desc       color.Color
+	DescSel    color.Color
+	SelBg      color.Color
+	ScrollInfo color.Color
+	GhostText  color.Color
 }
 
 var currentTheme = Theme{
@@ -412,6 +414,29 @@ func truncateToWidth(s string, maxW int) string {
 	return sb.String()
 }
 
+// titledEdge renders one horizontal box edge (top or bottom) with styled
+// content embedded in the dash run. inner is the width between corners.
+// leftPad positions the content that many dashes from the left corner;
+// pass -1 to center the content (classic style).
+func titledEdge(left, right string, inner int, content string, border lipgloss.Style, leftPad int) string {
+	contentWidth := lipgloss.Width(content)
+	if content == "" {
+		return border.Render(left + strings.Repeat("─", inner) + right)
+	}
+	leftDash := leftPad
+	if leftPad < 0 {
+		leftDash = max((inner-contentWidth)/2, 0)
+	}
+	rightDash := inner - leftDash - contentWidth
+	if rightDash < 0 {
+		leftDash = max(leftDash+rightDash, 0)
+		rightDash = 0
+	}
+	return border.Render(left+strings.Repeat("─", leftDash)) +
+		content +
+		border.Render(strings.Repeat("─", rightDash)+right)
+}
+
 func (o *Overlay) GetGhostText(buffer string, cursorAtEnd bool) string {
 	o.mu.Lock()
 	defer o.mu.Unlock()
@@ -644,24 +669,13 @@ func (o *Overlay) draw() string {
 
 	scrollInfo := ""
 	if len(o.Items) > windowSize {
-		scrollInfo = fmt.Sprintf(" %d/%d ", o.Cursor+1, len(o.Items))
+		scrollInfo = scrollStyle.Render(fmt.Sprintf(" %d/%d ", o.Cursor+1, len(o.Items)))
 	}
-	leftDash := 3
-	if isClassic && scrollInfo != "" {
-		leftDash = (inner - len(scrollInfo)) / 2
+	scrollPad := 3
+	if isClassic {
+		scrollPad = -1 // centered
 	}
-	rightDash := inner - leftDash - len(scrollInfo)
-	if scrollInfo == "" {
-		leftDash = 0
-		rightDash = inner
-	}
-	fmt.Fprintf(&s, "%s%s%s%s%s",
-		border.Render("╭"),
-		border.Render(strings.Repeat("─", leftDash)),
-		scrollStyle.Render(scrollInfo),
-		border.Render(strings.Repeat("─", rightDash)),
-		border.Render("╮"),
-	)
+	s.WriteString(titledEdge("╭", "╮", inner, scrollInfo, border, scrollPad))
 
 	// left and right side border with item rows
 	descW := 24
@@ -792,23 +806,7 @@ func (o *Overlay) draw() string {
 		footerInfo = fmt.Sprintf(" %s%s • %s%s ", selectKey, acceptText, ctrlRKey, modeText)
 	}
 
-	footerRunes := lipgloss.Width(footerInfo)
-	rightDash = 2
-	leftDash = inner - footerRunes - rightDash
-	if footerInfo == "" {
-		leftDash = 0
-		rightDash = inner
-	}
-	if leftDash < 0 {
-		leftDash = 0
-	}
-	fmt.Fprintf(&s, "%s%s%s%s%s",
-		border.Render("╰"),
-		border.Render(strings.Repeat("─", leftDash)),
-		footerInfo,
-		border.Render(strings.Repeat("─", rightDash)),
-		border.Render("╯"),
-	)
+	s.WriteString(titledEdge("╰", "╯", inner, footerInfo, border, inner-lipgloss.Width(footerInfo)-2))
 
 	s.WriteString("\0338")
 	s.WriteString("\033[?7h")