feat: add fail-closed Hub access profile foundation

Assistant: codex
Assistant-Model: gpt-6-astra
Assistant-Session: 01a0e747-8f27-7242-8df8-8bc44f88c929

hub_core/runtime/config.py

@@ -38,9 +38,21 @@ class RuntimeSettings:
     legacy_health: bool = False
     statehub_inbox_reads: bool = False
     statehub_inbox_agent: str = "state-hub"
+    access_mode: str = "auto"
+
+    @property
+    def enforce_access(self) -> bool:
+        return self.access_mode == "enforce" or (
+            self.access_mode == "auto" and self.environment not in {"development", "test"}
+        )
 
     def __post_init__(self) -> None:
-        if self.statehub_inbox_reads and (self.backend != "postgresql" or not self.api_token):
+        if self.access_mode not in {"auto", "enforce", "development"}:
+            raise ValueError("unsupported access mode")
+        if self.access_mode == "development" and self.environment not in {"development", "test"}:
+            raise ValueError("development access is forbidden outside development/test")
+        if self.statehub_inbox_reads and (self.backend != "postgresql" or
+                                         (not self.enforce_access and not self.api_token)):
             raise ValueError("State Hub inbox reads require PostgreSQL and operator token")
         if self.repo_manager_timeout_seconds <= 0:
             raise ValueError("Repo Manager timeout must be positive")
@@ -87,6 +99,7 @@ class RuntimeSettings:
             legacy_health=_env_bool("HUB_CORE_LEGACY_HEALTH", False),
             statehub_inbox_reads=_env_bool("HUB_CORE_STATEHUB_INBOX_READS", False),
             statehub_inbox_agent=os.getenv("HUB_CORE_STATEHUB_INBOX_AGENT", "state-hub"),
+            access_mode=os.getenv("HUB_CORE_ACCESS_MODE", "auto"),
         )
 
     def readiness_checks(self, store_backend: str) -> dict[str, str]:
@@ -99,7 +112,8 @@ class RuntimeSettings:
             "operator",
         }
         authorization_ready = (
-            not protected_groups
+            self.enforce_access
+            or not protected_groups
             or bool(self.api_token)
             or store_backend == "postgresql"
         )