refactor(ui): standardize on lipgloss semantic color system

Replace all fatih/color usages with internal/ui package that provides:
- Semantic color tokens (Pass, Warn, Fail, Accent, Muted)
- Adaptive light/dark mode support via Lipgloss AdaptiveColor
- Ayu theme colors for consistent, accessible output
- Tufte-inspired data-ink ratio principles

Files migrated: 35 command files in cmd/bd/

Add docs/ui-philosophy.md documenting:
- Semantic token usage guidelines
- Light/dark terminal optimization rationale
- Tufte and perceptual UI/UX theory application
- When to use (and not use) color in CLI output

cmd/bd/label.go

@@ -7,15 +7,16 @@ import (
 	"os"
 	"sort"
 	"strings"
-	"github.com/fatih/color"
 	"github.com/spf13/cobra"
 	"github.com/steveyegge/beads/internal/rpc"
 	"github.com/steveyegge/beads/internal/types"
+	"github.com/steveyegge/beads/internal/ui"
 	"github.com/steveyegge/beads/internal/utils"
 )
 var labelCmd = &cobra.Command{
-	Use:   "label",
-	Short: "Manage issue labels",
+	Use:     "label",
+	GroupID: "issues",
+	Short:   "Manage issue labels",
 }
 // Helper function to process label operations for multiple issues
 func processBatchLabelOperation(issueIDs []string, label string, operation string, jsonOut bool,
@@ -40,14 +41,13 @@ func processBatchLabelOperation(issueIDs []string, label string, operation strin
 				"label":    label,
 			})
 		} else {
-			green := color.New(color.FgGreen).SprintFunc()
 			verb := "Added"
 			prep := "to"
 			if operation == "removed" {
 				verb = "Removed"
 				prep = "from"
 			}
-			fmt.Printf("%s %s label '%s' %s %s\n", green("✓"), verb, label, prep, issueID)
+			fmt.Printf("%s %s label '%s' %s %s\n", ui.RenderPass("✓"), verb, label, prep, issueID)
 		}
 	}
 	if len(issueIDs) > 0 && daemonClient == nil {
@@ -217,8 +217,7 @@ var labelListCmd = &cobra.Command{
 			fmt.Printf("\n%s has no labels\n", issueID)
 			return
 		}
-		cyan := color.New(color.FgCyan).SprintFunc()
-		fmt.Printf("\n%s Labels for %s:\n", cyan("🏷"), issueID)
+		fmt.Printf("\n%s Labels for %s:\n", ui.RenderAccent("🏷"), issueID)
 		for _, label := range labels {
 			fmt.Printf("  - %s\n", label)
 		}
@@ -302,8 +301,7 @@ var labelListAllCmd = &cobra.Command{
 			outputJSON(result)
 			return
 		}
-		cyan := color.New(color.FgCyan).SprintFunc()
-		fmt.Printf("\n%s All labels (%d unique):\n", cyan("🏷"), len(labels))
+		fmt.Printf("\n%s All labels (%d unique):\n", ui.RenderAccent("🏷"), len(labels))
 		// Find longest label for alignment
 		maxLen := 0
 		for _, label := range labels {