refactor(mol): split 1218-line mol.go into subcommand files

Split monolithic mol.go into 7 focused files:
- mol.go (76 lines): root command, shared constants
- mol_catalog.go (83): bd mol catalog
- mol_show.go (76): bd mol show
- mol_spawn.go (238): bd mol spawn
- mol_run.go (137): bd mol run
- mol_bond.go (382): bd mol bond + helpers
- mol_distill.go (307): bd mol distill + helpers

Closes bd-cnwx

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

cmd/bd/mol_show.go

@@ -0,0 +1,76 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+	"github.com/steveyegge/beads/internal/ui"
+	"github.com/steveyegge/beads/internal/utils"
+)
+
+var molShowCmd = &cobra.Command{
+	Use:   "show <molecule-id>",
+	Short: "Show molecule details",
+	Args:  cobra.ExactArgs(1),
+	Run: func(cmd *cobra.Command, args []string) {
+		ctx := rootCtx
+
+		// mol show requires direct store access for subgraph loading
+		if store == nil {
+			if daemonClient != nil {
+				fmt.Fprintf(os.Stderr, "Error: mol show requires direct database access\n")
+				fmt.Fprintf(os.Stderr, "Hint: use --no-daemon flag: bd --no-daemon mol show %s\n", args[0])
+			} else {
+				fmt.Fprintf(os.Stderr, "Error: no database connection\n")
+			}
+			os.Exit(1)
+		}
+
+		moleculeID, err := utils.ResolvePartialID(ctx, store, args[0])
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Error: molecule '%s' not found\n", args[0])
+			os.Exit(1)
+		}
+
+		subgraph, err := loadTemplateSubgraph(ctx, store, moleculeID)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Error loading molecule: %v\n", err)
+			os.Exit(1)
+		}
+
+		showMolecule(subgraph)
+	},
+}
+
+func showMolecule(subgraph *MoleculeSubgraph) {
+	if jsonOutput {
+		outputJSON(map[string]interface{}{
+			"root":         subgraph.Root,
+			"issues":       subgraph.Issues,
+			"dependencies": subgraph.Dependencies,
+			"variables":    extractAllVariables(subgraph),
+		})
+		return
+	}
+
+	fmt.Printf("\n%s Molecule: %s\n", ui.RenderAccent("🧪"), subgraph.Root.Title)
+	fmt.Printf("   ID: %s\n", subgraph.Root.ID)
+	fmt.Printf("   Steps: %d\n", len(subgraph.Issues))
+
+	vars := extractAllVariables(subgraph)
+	if len(vars) > 0 {
+		fmt.Printf("\n%s Variables:\n", ui.RenderWarn("📝"))
+		for _, v := range vars {
+			fmt.Printf("   {{%s}}\n", v)
+		}
+	}
+
+	fmt.Printf("\n%s Structure:\n", ui.RenderPass("🌲"))
+	printMoleculeTree(subgraph, subgraph.Root.ID, 0, true)
+	fmt.Println()
+}
+
+func init() {
+	molCmd.AddCommand(molShowCmd)
+}