Ignore client rigs at the repo root, before rig's tree lands

A rig is a copy of rig/ renamed after the environment it models, so its k8s
files spell out a real architecture — the one thing that must not be committed
here. rig/.gitignore already refuses them, but only within rig/: a copy is a
SIBLING of rig/, where that file has no reach. spr had no rule at all, so the
first `git add -A` after the fold would have committed one.

Anchored at the root, and the negation names the full path because `*-rig/` is
unanchored and would otherwise match rig/sample-rig too.

Verified both ways: a file under client-rig/ is ignored, one under
rig/sample-rig/ is not.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

.gitignore

@@ -34,3 +34,13 @@ cfg/amar/
 cfg/dlt/
 # Add new rooms here as they are created
 # cfg/<room>/
+
+# Client rigs. A rig is a copy of rig/ renamed after the environment it models,
+# so its k8s files spell out a real architecture — exactly the thing that must
+# not land here. They are versioned in their own repo.
+#
+# Anchored at the ROOT on purpose: a copy is a SIBLING of rig/, so a rule inside
+# rig/.gitignore cannot see it. The negation must name the full path for the same
+# reason — `*-rig/` is unanchored and matches at any depth, including rig/sample-rig.
+*-rig/
+!rig/sample-rig/