Chore: regenerate docs navigation

Auto-generated-by: update-generated-files-action; https://github.com/OpenRouterTeam/python-sdk/actions/runs/36756596341

Author: github-actions[bot]

docs/docs.json

@@ -24,6 +24,7 @@
       "sdks/decisions/README",
       "sdks/embeddings/README",
       "sdks/endpoints/README",
+      "sdks/endusers/README",
       "sdks/files/README",
       "sdks/generations/README",
       "sdks/guardrails/README",