docs(agents): rename triage-labels column to Canonical role

Drop the leftover 'Label in mattpocock/skills' seed-template header; the
column is the canonical role name, mapped to our tracker's label.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: lesnik512

planning/agents/triage-labels.md

@@ -2,7 +2,7 @@
 
 The skills speak in terms of five canonical triage roles. This file maps those roles to the actual label strings used in this repo's issue tracker.
 
-| Label in mattpocock/skills | Label in our tracker | Meaning                                  |
+| Canonical role             | Label in our tracker | Meaning                                  |
 | -------------------------- | -------------------- | ---------------------------------------- |
 | `needs-triage`             | `needs-triage`       | Maintainer needs to evaluate this issue  |
 | `needs-info`               | `needs-info`         | Waiting on reporter for more information |