Revert "test(budget): capy/skill/gstack ceiling 5316 after the main merge"

This reverts commit 61a9051b4a.

test/fixtures/context-budget.json

@@ -9,7 +9,7 @@
     "browser-skills/hackernews-frontpage": 371,
     "canary": 7738,
     "captain": 6551,
-    "capy/skill/gstack": 5316,
+    "capy/skill/gstack": 5315,
     "careful": 1239,
     "codex": 9890,
     "context-restore": 6287,