feat: add hub runtime and extension contract

hub_core/runtime/config.py

@@ -0,0 +1,59 @@
+from __future__ import annotations
+
+import os
+from dataclasses import dataclass
+
+
+def _env_bool(name: str, default: bool) -> bool:
+    raw = os.getenv(name)
+    if raw is None:
+        return default
+    return raw.strip().lower() in {"1", "true", "yes", "on"}
+
+
+@dataclass(frozen=True, slots=True)
+class RuntimeSettings:
+    environment: str = "development"
+    backend: str = "memory"
+    allow_ephemeral: bool = True
+    api_host: str = "127.0.0.1"
+    api_port: int = 8010
+    api_base: str = "http://127.0.0.1:8010"
+    mcp_host: str = "127.0.0.1"
+    mcp_port: int = 8011
+    mcp_transport: str = "http"
+    database_url: str | None = None
+
+    @classmethod
+    def from_env(cls) -> RuntimeSettings:
+        environment = os.getenv("HUB_CORE_ENV", "development")
+        default_ephemeral = environment in {"development", "test"}
+        api_host = os.getenv("HUB_CORE_API_HOST", "127.0.0.1")
+        api_port = int(os.getenv("HUB_CORE_API_PORT", "8010"))
+        return cls(
+            environment=environment,
+            backend=os.getenv("HUB_CORE_BACKEND", "memory"),
+            allow_ephemeral=_env_bool("HUB_CORE_ALLOW_EPHEMERAL", default_ephemeral),
+            api_host=api_host,
+            api_port=api_port,
+            api_base=os.getenv("HUB_CORE_API_BASE", f"http://127.0.0.1:{api_port}"),
+            mcp_host=os.getenv("HUB_CORE_MCP_HOST", "127.0.0.1"),
+            mcp_port=int(os.getenv("HUB_CORE_MCP_PORT", "8011")),
+            mcp_transport=os.getenv("HUB_CORE_MCP_TRANSPORT", "http"),
+            database_url=os.getenv("HUB_CORE_DATABASE_URL") or os.getenv("DATABASE_URL"),
+        )
+
+    def readiness_checks(self, store_backend: str) -> dict[str, str]:
+        ephemeral_allowed = store_backend != "memory" or self.allow_ephemeral
+        return {
+            "environment": self.environment,
+            "configured_backend": self.backend,
+            "active_backend": store_backend,
+            "ephemeral_backend": "allowed" if ephemeral_allowed else "not_allowed",
+            "contract": "helixforge.hub-extension/0.1.0",
+        }
+
+    def is_ready(self, store_backend: str) -> bool:
+        return self.backend == store_backend and (
+            store_backend != "memory" or self.allow_ephemeral
+        )