feat(auth): define Default/Local owner contract (#5795)

* feat(auth): define default local owner contract

* test(auth): harden default local owner matrix

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Co-authored-by: Alexandre Teixeira <111787685+alteixeira20@users.noreply.github.com>

routes/research/research_routes.py

@@ -15,7 +15,7 @@ from pydantic import BaseModel, Field
 from core.middleware import INTERNAL_TOOL_USER
 from src.endpoint_resolver import resolve_endpoint
 from src.auth_helpers import _auth_disabled, get_current_user
-from core.auth import RESERVED_USERNAMES
+from src.owner_identity import REQUEST_SENTINEL_OWNERS
 from src.constants import DEEP_RESEARCH_DIR
 
 _SESSION_ID_RE = re.compile(r"^[a-zA-Z0-9-]{1,128}$")
@@ -496,7 +496,7 @@ def setup_research_routes(research_handler, session_manager=None) -> APIRouter:
         user = require_privilege(request, "can_use_research")
         if user == INTERNAL_TOOL_USER:
             tool_owner = (request.headers.get("X-Odysseus-Owner") or "").strip()
-            if tool_owner and tool_owner not in RESERVED_USERNAMES:
+            if tool_owner and tool_owner not in REQUEST_SENTINEL_OWNERS:
                 auth_mgr = getattr(request.app.state, "auth_manager", None)
                 if auth_mgr is not None and getattr(auth_mgr, "is_configured", False):
                     try: