docs: Add prefix-based routing to all role templates

Explains how bd commands route to the correct rig based on issue
prefix, and documents routes.jsonl location and debug mode.

Updated templates:
- mayor.md.tmpl (full section)
- crew.md.tmpl (full section)
- polecat.md.tmpl (full section)
- witness.md.tmpl (compact note)
- refinery.md.tmpl (compact note)
- deacon.md.tmpl (full section)

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

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

internal/templates/roles/refinery.md.tmpl

@@ -149,6 +149,8 @@ gt mail send {{ .RigName }}/<worker> -s "Rebase needed" \
 - `bd close <id>` - Close issue after merge
 - `bd sync` - Sync beads changes
 
+**Prefix-based routing:** `bd show gt-xyz` works from anywhere - routes via `~/gt/.beads/routes.jsonl`.
+
 ## Session Cycling
 
 When your context fills up: