Remove broken slot set for convoy notify address (gt-733mx)

The `bd slot` command is for agent beads only. Convoy beads aren't agents,
so the slot set failed with exit status 1. The notify address is already
stored in the convoy's description, which is the intended persistence
mechanism.

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

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

internal/cmd/convoy.go

@@ -193,15 +193,7 @@ func runConvoyCreate(cmd *cobra.Command, args []string) error {
 		return fmt.Errorf("creating convoy: %w (%s)", err, strings.TrimSpace(stderr.String()))
 	}
 
-	// Store notify address in slot if specified (for convoy-cleanup to read)
-	if convoyNotify != "" {
-		slotArgs := []string{"slot", "set", convoyID, "notify", convoyNotify}
-		slotCmd := exec.Command("bd", slotArgs...)
-		slotCmd.Dir = townBeads
-		if err := slotCmd.Run(); err != nil {
-			style.PrintWarning("couldn't set notify slot: %v", err)
-		}
-	}
+	// Notify address is stored in description (line 166-168) and read from there
 
 	// Add 'tracks' relations for each tracked issue
 	trackedCount := 0