feat: add ChatGPT Subscription provider (#2876)

* feat: Add ChatGPT Subscription support and related features

- Introduced a new provider option for ChatGPT Subscription in the endpoint selection UI.
- Implemented OAuth flow for ChatGPT Subscription sign-in, including polling for authorization status.
- Updated admin interface to handle ChatGPT Subscription, including disabling API key input and providing user guidance.
- Enhanced cost tracking logic to differentiate between subscription and non-subscription endpoints.
- Added new slash commands for managing skills, including listing, searching, and invoking skills.
- Implemented caching for skill catalog to optimize performance.
- Updated tests to cover new ChatGPT Subscription functionality and ensure proper endpoint probing.
- Refactored existing code to accommodate new features and improve maintainability.

* refactor: share provider device-flow setup

- reuse one device-flow backend for Copilot and ChatGPT Subscription
- add one frontend device-flow helper for Settings and /setup
- put GitHub Copilot back into Add Models, now as a dropdown option
- make provider selection just select; clicking Add starts sign-in
- stop ChatGPT Subscription setup from opening auth tabs automatically
- make /setup copilot and /setup chatgpt-subscription work from chat
- show ChatGPT Subscription in the /setup suggestions
- show the real error message when setup fails
- add focused tests for the shared flow and setup UI

* feat(chatgpt-subscription): harden credential lifecycle and streamline auth UX

Backend:
- Resolve runtime bearer for provider-auth endpoints at probe time via a
  shared _resolve_probe_key() that delegates to resolve_endpoint_runtime,
  applied across all probe/refresh call sites.
- Skip live completion probes and health pings for discovery-only providers
  (centralized behind _is_discovery_only_provider) — the Codex/Responses API
  has no such endpoints, so status is derived from cached models.
- Never persist the short lived ChatGPT bearer to the plaintext sessions
  table; proactively clear any stale bearer left by an earlier code path.
- Revoke orphaned ProviderAuthSession credentials when the last endpoint
  backing them is deleted (_delete_orphaned_provider_auth), surfaced via
  cleared_provider_auth in the delete response.

Frontend (admin.js):
- Auto-start the device-auth flow on provider selection so the authorization
  panel (code + Authorize) shows immediately instead of behind a "Sign in" click.
- Remove the redundant top button for device auth providers, move retry
  into the panel via an inline "Try again".
- Drop the self-evident hint text and add an execCommand clipboard fallback so
  Copy works in non-secure (HTTP/LAN) contexts.

* fix: harden chatgpt subscription provider

* chore: remove PR media from branch

* Fix chatgpt subscription recovery and token handling

---------

Co-authored-by: 5p00kyy <admin@5p00ky.dev>

tests/test_research_endpoint_owner_scope.py

@@ -24,7 +24,7 @@ _sd = types.ModuleType("src.database")
 _sd.ModelEndpoint = MagicMock()
 sys.modules.setdefault("src.database", _sd)
 
-from routes.research_routes import _owned_enabled_endpoint  # noqa: E402
+from routes.research_routes import _owned_enabled_endpoint, _resolve_endpoint_runtime  # noqa: E402
 
 
 class _Predicate:
@@ -129,3 +129,29 @@ def test_null_owner_is_legacy_single_user_noop():
     rows = [_ep("ep-x", "bob"), _ep("ep-y", "alice")]
     ep = _resolve(rows, None, "ep-x")
     assert ep is not None and ep.id == "ep-x"
+
+
+def test_runtime_resolution_uses_provider_auth_for_chatgpt_subscription(monkeypatch):
+    ep = SimpleNamespace(
+        id="ep-chatgpt",
+        owner="alice",
+        base_url="https://chatgpt.com/backend-api/codex",
+        api_key=None,
+        provider_auth_id="auth-1",
+        cached_models='["gpt-5.5"]',
+        hidden_models=None,
+    )
+
+    monkeypatch.setattr(
+        "src.chatgpt_subscription.resolve_runtime_credentials",
+        lambda auth_id, owner=None: {
+            "base_url": "https://chatgpt.com/backend-api/codex",
+            "api_key": "fresh-access-token",
+        },
+    )
+
+    url, model, headers = _resolve_endpoint_runtime(ep, owner="alice", model="")
+
+    assert url == "https://chatgpt.com/backend-api/codex/responses"
+    assert model == "gpt-5.5"
+    assert headers["Authorization"] == "Bearer fresh-access-token"