fix(loadouts): claude_loadout read through CONFIG_BIN; capy skill context ceiling for the --model line (GSTA-161)

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

test/fixtures/context-budget.json

@@ -9,7 +9,7 @@
     "browser-skills/hackernews-frontpage": 371,
     "canary": 7738,
     "captain": 6551,
-    "capy/skill/gstack": 5136,
+    "capy/skill/gstack": 5690,
     "careful": 1239,
     "codex": 9890,
     "context-restore": 6287,