Address cubic review: classify partial probe failures and download errors as network

- `_detect_item_type`: a transport failure on either probe (when no 200 winner exists) now raises `network`, not `not-found`. Mixing a 404 on one endpoint with a 5xx or transport failure on the other previously fell through to `not-found`, which masked real connectivity problems. Identified by cubic.
- `get`: wrap the post-detect download calls so `httpx.HTTPError` (transport failures and 5xx via `raise_for_status`) raises `_fail("network", ...)` (exit 2) instead of being swallowed by the default `@catch_exception` exit 1. Identified by cubic.
- Update quickstart success example to match the actual `Downloaded schema …` output.
- Add three tests: partial probe failure -> network, versioned download network error, and `--collection` flag network error.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: minitriga

dev/specs/001-marketplace-api-update/quickstart.md

@@ -66,7 +66,7 @@ This must exercise the same auto-detection behaviour against the overridden host
 For a schema:
 
 ```text
-Downloaded acme/network-base v1.2.0 -> schemas/network-base.yml
+Downloaded schema acme/network-base v1.2.0 -> schemas/network-base.yml
 ```
 
 For a collection:

infrahub_sdk/ctl/marketplace.py

@@ -105,7 +105,7 @@ def is_transport_failure(r: object) -> bool:
             return True
         return isinstance(r, httpx.Response) and r.status_code >= 500
 
-    if is_transport_failure(schema_resp) and is_transport_failure(collection_resp):
+    if is_transport_failure(schema_resp) or is_transport_failure(collection_resp):
         raise _fail(
             "network",
             f"Could not reach marketplace at {base_url}. Check your connection or --marketplace-url.",
@@ -279,13 +279,16 @@ async def get(
         else:
             item_type = "schema"
 
-        if item_type == "collection":
-            if version:
-                _status(stdout).print("[yellow]Warning: --version is ignored when downloading a collection.")
-            await _download_collection(
-                client, base_url, namespace, name, output_dir, stdout=stdout, prefetched=prefetched
-            )
-        else:
-            await _download_schema(
-                client, base_url, namespace, name, version, output_dir, stdout=stdout, prefetched=prefetched
-            )
+        try:
+            if item_type == "collection":
+                if version:
+                    _status(stdout).print("[yellow]Warning: --version is ignored when downloading a collection.")
+                await _download_collection(
+                    client, base_url, namespace, name, output_dir, stdout=stdout, prefetched=prefetched
+                )
+            else:
+                await _download_schema(
+                    client, base_url, namespace, name, version, output_dir, stdout=stdout, prefetched=prefetched
+                )
+        except httpx.HTTPError as exc:
+            raise _fail("network", f"Marketplace request failed: {exc}") from exc

tests/unit/ctl/test_marketplace_app.py

@@ -449,6 +449,60 @@ def test_download_collection_with_skipped(httpx_mock: HTTPXMock, tmp_path: Path)
     assert "1/2 schemas downloaded" in result.stdout
 
 
+def test_autodetect_partial_probe_failure_is_network(httpx_mock: HTTPXMock, tmp_path: Path) -> None:
+    """Schema 404 + collection transport failure should be classified as network, not not-found."""
+    httpx_mock.add_response(
+        method="GET",
+        url="https://marketplace.infrahub.app/api/v1/schemas/acme/foo/download",
+        status_code=404,
+        json={"detail": "Schema not found"},
+    )
+    httpx_mock.add_exception(
+        httpx.ConnectError("connection refused"),
+        url="https://marketplace.infrahub.app/api/v1/collections/acme/foo/download",
+    )
+    result = runner.invoke(app, ["get", "acme/foo", "-o", str(tmp_path)])
+
+    assert result.exit_code == 2
+    assert "Could not reach marketplace" in result.stdout
+
+
+def test_versioned_download_network_error(httpx_mock: HTTPXMock, tmp_path: Path) -> None:
+    """A network failure during the post-detect versioned fetch should exit with code 2."""
+    httpx_mock.add_response(
+        method="GET",
+        url="https://marketplace.infrahub.app/api/v1/schemas/acme/network-base/download",
+        text=SCHEMA_YAML,
+        headers={"x-schema-version": "1.2.0"},
+    )
+    httpx_mock.add_response(
+        method="GET",
+        url="https://marketplace.infrahub.app/api/v1/collections/acme/network-base/download",
+        status_code=404,
+        json={"detail": "Collection not found"},
+    )
+    httpx_mock.add_exception(
+        httpx.ConnectError("connection refused"),
+        url="https://marketplace.infrahub.app/api/v1/schemas/acme/network-base/versions/1.0.0/download",
+    )
+    result = runner.invoke(app, ["get", "acme/network-base", "-v", "1.0.0", "-o", str(tmp_path)])
+
+    assert result.exit_code == 2
+    assert "Marketplace request failed" in result.stdout
+
+
+def test_collection_flag_network_error(httpx_mock: HTTPXMock, tmp_path: Path) -> None:
+    """A network failure on the explicit --collection fetch should exit with code 2."""
+    httpx_mock.add_exception(
+        httpx.ConnectError("connection refused"),
+        url="https://marketplace.infrahub.app/api/v1/collections/acme/foo/download",
+    )
+    result = runner.invoke(app, ["get", "acme/foo", "-c", "-o", str(tmp_path)])
+
+    assert result.exit_code == 2
+    assert "Marketplace request failed" in result.stdout
+
+
 def test_get_schema_stdout(httpx_mock: HTTPXMock, tmp_path: Path) -> None:
     httpx_mock.add_response(
         method="GET",