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>

routes/webhook_routes.py

@@ -325,22 +325,33 @@ def setup_webhook_routes(
             endpoint_url = build_chat_url(base_url)
             model = body.model or "auto"
             api_key = ep.api_key
+            if getattr(ep, "provider_auth_id", None):
+                try:
+                    from src.endpoint_resolver import resolve_endpoint_runtime
+                    base_url, api_key = resolve_endpoint_runtime(ep, owner=token_owner)
+                    endpoint_url = build_chat_url(base_url)
+                except Exception:
+                    raise HTTPException(500, "Could not resolve endpoint credentials")
 
             if model == "auto":
                 try:
                     async with httpx.AsyncClient(timeout=5) as client:
                         models_url = build_models_url(base_url)
                         hdrs = build_headers(api_key, base_url)
-                        resp = await client.get(models_url, headers=hdrs)
-                        resp.raise_for_status()
-                        data = resp.json()
-                        ids = [m.get("id") for m in (data.get("data") or []) if m.get("id")]
-                        if not ids:
-                            ids = [
-                                m.get("name") or m.get("model")
-                                for m in (data.get("models") or [])
-                                if m.get("name") or m.get("model")
-                            ]
+                        if models_url:
+                            resp = await client.get(models_url, headers=hdrs)
+                            resp.raise_for_status()
+                            data = resp.json()
+                            ids = [m.get("id") for m in (data.get("data") or []) if m.get("id")]
+                            if not ids:
+                                ids = [
+                                    m.get("name") or m.get("model")
+                                    for m in (data.get("models") or [])
+                                    if m.get("name") or m.get("model")
+                                ]
+                        else:
+                            import json as _json
+                            ids = _json.loads(ep.cached_models or "[]")
                         model = ids[0] if ids else "auto"
                 except Exception:
                     raise HTTPException(500, "Could not discover models from endpoint")