fix(extensions,presets,workflows): resolve private GHES release assets via /api/v3 (#3157)

* feat(auth): add github_provider_hosts() to enumerate GHES hosts from auth.json

Assisted-by: Claude Code (model: claude-sonnet-4-6, autonomous)

* fix(extensions): resolve GHES release assets via /api/v3

Generalizes resolve_github_release_asset_api_url to GitHub Enterprise
Server hosts (gated by auth.json github hosts), fixing private GHES
extension/preset downloads. github/spec-kit#3147

Assisted-by: Claude Code (model: claude-sonnet-4-6, autonomous)

* fix(extensions,presets): pass auth.json github hosts into release resolver

Assisted-by: Claude Code (model: claude-sonnet-4-6, autonomous)

* docs(auth): document GHES private catalog + release-asset auth

Assisted-by: Claude Code (model: claude-sonnet-4-6, autonomous)

* fix(presets,workflows): pass auth.json github hosts into remaining release resolvers

Wires preset add --from and workflow add through github_provider_hosts()
so private GHES release assets resolve via /api/v3 there too. github/spec-kit#3147

Assisted-by: Claude Code (model: claude-sonnet-4-6, autonomous)

* test(presets): use module-level io.BytesIO in GHES preset test

Addresses Copilot review on PR #3157: drop unnecessary __import__("io")
in test_preset_add_from_ghes_release_url_resolves_via_api_v3 since io is
already imported at module level.

* fix(github-http): pass through GHES asset API URLs by path shape

Addresses Copilot review on PR #3157. A direct GHES /api/v3 release asset
URL was only returned as already-resolved when its host was in the
allowlist; otherwise the resolver returned None and the caller downloaded
the same URL without 'Accept: application/octet-stream', fetching JSON
metadata instead of the binary.

Gate the passthrough on path shape alone, mirroring the github.com case.
This is safe: passthrough returns the input URL unchanged and the caller
fetches it either way, so no new request to an arbitrary host is induced;
the token stays independently gated by auth.json in open_url. The
allowlist remains the anti-SSRF gate on the tag-lookup resolving path.

Add test_passthrough_for_unlisted_ghes_api_asset_url.

src/specify_cli/presets/__init__.py

@@ -1892,10 +1892,19 @@ class PresetCatalog:
         download_url: str,
         timeout: int = 60,
     ) -> Optional[str]:
-        """Resolve a GitHub release asset URL to its REST API asset URL."""
+        """Resolve a GitHub release asset URL to its REST API asset URL.
+
+        Passes the ``github`` provider hosts from ``auth.json`` so GitHub
+        Enterprise Server release assets resolve via ``/api/v3``.
+        """
         from specify_cli._github_http import resolve_github_release_asset_api_url
+        from specify_cli.authentication.http import github_provider_hosts
+
         return resolve_github_release_asset_api_url(
-            download_url, self._open_url, timeout=timeout
+            download_url,
+            self._open_url,
+            timeout=timeout,
+            github_hosts=github_provider_hosts(),
         )
 
     def _validate_catalog_payload(self, catalog_data: Any, url: str) -> None:

src/specify_cli/presets/_commands.py

@@ -144,10 +144,13 @@ def preset_add(
                 zip_path = Path(tmpdir) / "preset.zip"
                 try:
                     from specify_cli.authentication.http import open_url as _open_url
+                    from specify_cli.authentication.http import github_provider_hosts
                     from specify_cli._github_http import resolve_github_release_asset_api_url
 
                     _preset_extra_headers = None
-                    _resolved_from_url = resolve_github_release_asset_api_url(from_url, _open_url)
+                    _resolved_from_url = resolve_github_release_asset_api_url(
+                        from_url, _open_url, github_hosts=github_provider_hosts()
+                    )
                     if _resolved_from_url:
                         from_url = _resolved_from_url
                         _preset_extra_headers = {"Accept": "application/octet-stream"}