feat: add command aliases for PGT parity (may, sess, ref, sp, cat, stat)

Add Cobra aliases to match PGT abbreviation support:
- mayor → may (gt may at now works)
- session → sess
- refinery → ref
- spawn → sp
- polecat → cat
- status → stat

This enables the same abbreviated commands that worked in PGT, like
"gt may at" to attach to the Mayor session.

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

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

internal/cmd/refinery.go

@@ -23,8 +23,9 @@ var (
 )
 
 var refineryCmd = &cobra.Command{
-	Use:   "refinery",
-	Short: "Manage the merge queue processor",
+	Use:     "refinery",
+	Aliases: []string{"ref"},
+	Short:   "Manage the merge queue processor",
 	Long: `Manage the Refinery merge queue processor for a rig.
 
 The Refinery processes merge requests from polecats, merging their work