docs: the tool creates 11 labels, not 12 -- I counted its own definition

Caught by the Pi agent against the live instance after Phase 4 ran. The tool
creates 5 state/*, 2 agent/*, 4 kind/* = 11.

Where the 12 came from is worth a line, because it is a shape that recurs:

    $ grep -c '^mklabel' tools/gitea-setup
    12
    $ grep -n '^mklabel' tools/gitea-setup | grep -v ':mklabel "'
    74:mklabel() { # name colour description

I counted the function DEFINITION as a call. A measurement taken one token away
from the thing being measured -- the same shape as reading protection off a
settings page and reachability off a DNS record, which is now three today. The
version that cannot make this mistake is counting what the instance holds, and
that is what found it.

docs/agents/GITEA-SETUP.md

@@ -208,7 +208,7 @@ tools/gitea-setup --dry-run   # read it first
 tools/gitea-setup             # idempotent; safe to re-run
 ```
 
-Creates 12 labels (the `state/*` set, `agent/*`, `kind/*`) and 4 milestones
+Creates 11 labels — 5 `state/*`, 2 `agent/*`, 4 `kind/*` — and 4 milestones
 (Menus, Title screen, Graphics pipeline, Infrastructure).
 
 **No Kanban board yet, on purpose.** Gitea's board does not follow labels, so it