fix: gt sling uses bd mol wisp instead of bd wisp (bd-hp8g)

The runSlingFormula function was calling bd wisp which does not exist.
The correct command is bd mol wisp for creating ephemeral molecules.

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

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

internal/cmd/sling.go

@@ -713,7 +713,7 @@ func runSlingFormula(args []string) error {
 
 	// Step 2: Create wisp instance (ephemeral)
 	fmt.Printf("  Creating wisp...\n")
-	wispArgs := []string{"wisp", formulaName}
+	wispArgs := []string{"mol", "wisp", formulaName}
 	for _, v := range slingVars {
 		wispArgs = append(wispArgs, "--var", v)
 	}