feat: introduce theme management and performance improvements (#7)

internal/theme/mono.go

@@ -0,0 +1,49 @@
+package theme
+
+import "github.com/charmbracelet/lipgloss"
+
+// createMonoTheme creates a monochrome theme (no colors)
+// useful for accessibility, piping output, or minimal terminals
+func createMonoTheme() *Theme {
+	baseStyle := lipgloss.NewStyle()
+	boldStyle := lipgloss.NewStyle().Bold(true)
+
+	return &Theme{
+		Name: "mono",
+		Styles: Styles{
+			Header:     boldStyle,
+			Border:     baseStyle,
+			Selected:   boldStyle,
+			Watched:    boldStyle,
+			Normal:     baseStyle,
+			Error:      boldStyle,
+			Success:    boldStyle,
+			Warning:    boldStyle,
+			Footer:     baseStyle,
+			Background: baseStyle,
+
+			Proto: ProtoStyles{
+				TCP:  baseStyle,
+				UDP:  baseStyle,
+				Unix: baseStyle,
+				TCP6: baseStyle,
+				UDP6: baseStyle,
+			},
+
+			State: StateStyles{
+				Listen:      baseStyle,
+				Established: baseStyle,
+				TimeWait:    baseStyle,
+				CloseWait:   baseStyle,
+				SynSent:     baseStyle,
+				SynRecv:     baseStyle,
+				FinWait1:    baseStyle,
+				FinWait2:    baseStyle,
+				Closing:     baseStyle,
+				LastAck:     baseStyle,
+				Closed:      baseStyle,
+			},
+		},
+	}
+}
+