fix: Use BeadsPath() for mq list to read from git-synced beads (gt-uhc3)

The mq list command was using r.Path (rig root) instead of r.BeadsPath()
which returns the mayor/rig clone path where beads are git-synced. This
caused the command to return empty results because it was looking at the
wrong .beads/ location.

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

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

internal/cmd/mq_list.go

@@ -20,8 +20,8 @@ func runMQList(cmd *cobra.Command, args []string) error {
 		return err
 	}
 
-	// Create beads wrapper for the rig
-	b := beads.New(r.Path)
+	// Create beads wrapper for the rig - use BeadsPath() to get the git-synced location
+	b := beads.New(r.BeadsPath())
 
 	// Build list options - query for merge-request type
 	// Priority -1 means no priority filter (otherwise 0 would filter to P0 only)