refactor: split flat core into capability packages, layer the conversations service, English defaults for every model-facing text

src/beaver_gateway/frontends/urls.py

@@ -0,0 +1,30 @@
+"""Where a frontend is reachable from outside, as seen by one request."""
+
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from starlette.requests import Request
+
+    from beaver_gateway.frontends.base import Frontend, GatewayRuntime
+
+
+def request_origin(request: Request, runtime: GatewayRuntime) -> str:
+    """``Gateway.public_url`` if configured, else the request's own origin."""
+    if runtime.public_url:
+        return runtime.public_url
+    host = request.headers.get("host")
+    if not host:
+        return f"http://{request.url.hostname}:{request.url.port}"
+    scheme = request.headers.get("x-forwarded-proto") or request.url.scheme
+    return f"{scheme}://{host}"
+
+
+def external_base(request: Request, runtime: GatewayRuntime) -> str:
+    """Origin plus the mount path of the app handling ``request``."""
+    return request_origin(request, runtime) + str(request.scope.get("root_path", ""))
+
+
+def frontend_url(request: Request, runtime: GatewayRuntime, fe: Frontend) -> str | None:
+    return request_origin(request, runtime) + fe.path if fe.path else None