Chore: regenerate docs navigation

Auto-generated-by: update-generated-files-action; https://github.com/OpenRouterTeam/python-sdk/actions/runs/35143634793

Author: github-actions[bot]

docs/docs.json

@@ -37,6 +37,7 @@
       "sdks/scim/README",
       "sdks/stt/README",
       "sdks/tts/README",
+      "sdks/vault/README",
       "sdks/videogeneration/README",
       "sdks/workspaces/README"
     ]