feat(qwen): add Qwen OAuth provider with portal request support

Based on #6079 by @tunamitom with critical fixes and comprehensive tests.

Changes from #6079:
- Fix: sanitization overwrite bug — Qwen message prep now runs AFTER codex
  field sanitization, not before (was silently discarding Qwen transforms)
- Fix: missing try/except AuthError in runtime_provider.py — stale Qwen
  credentials now fall through to next provider on auto-detect
- Fix: 'qwen' alias conflict — bare 'qwen' stays mapped to 'alibaba'
  (DashScope); use 'qwen-portal' or 'qwen-cli' for the OAuth provider
- Fix: hardcoded ['coder-model'] replaced with live API fetch + curated
  fallback list (qwen3-coder-plus, qwen3-coder)
- Fix: extract _is_qwen_portal() helper + _qwen_portal_headers() to replace
  5 inline 'portal.qwen.ai' string checks and share headers between init
  and credential swap
- Fix: add Qwen branch to _apply_client_headers_for_base_url for mid-session
  credential swaps
- Fix: remove suspicious TypeError catch blocks around _prompt_provider_choice
- Fix: handle bare string items in content lists (were silently dropped)
- Fix: remove redundant dict() copies after deepcopy in message prep
- Revert: unrelated ai-gateway test mock removal and model_switch.py comment deletion

New tests (30 test functions):
- _qwen_cli_auth_path, _read_qwen_cli_tokens (success + 3 error paths)
- _save_qwen_cli_tokens (roundtrip, parent creation, permissions)
- _qwen_access_token_is_expiring (5 edge cases: fresh, expired, within skew,
  None, non-numeric)
- _refresh_qwen_cli_tokens (success, preserve old refresh, 4 error paths,
  default expires_in, disk persistence)
- resolve_qwen_runtime_credentials (fresh, auto-refresh, force-refresh,
  missing token, env override)
- get_qwen_auth_status (logged in, not logged in)
- Runtime provider resolution (direct, pool entry, alias)
- _build_api_kwargs (metadata, vl_high_resolution_images, message formatting,
  max_tokens suppression)

hermes_cli/status.py

@@ -153,12 +153,14 @@ def show_status(args):
     print(color("◆ Auth Providers", Colors.CYAN, Colors.BOLD))
 
     try:
-        from hermes_cli.auth import get_nous_auth_status, get_codex_auth_status
+        from hermes_cli.auth import get_nous_auth_status, get_codex_auth_status, get_qwen_auth_status
         nous_status = get_nous_auth_status()
         codex_status = get_codex_auth_status()
+        qwen_status = get_qwen_auth_status()
     except Exception:
         nous_status = {}
         codex_status = {}
+        qwen_status = {}
 
     nous_logged_in = bool(nous_status.get("logged_in"))
     print(
@@ -189,6 +191,21 @@ def show_status(args):
     if codex_status.get("error") and not codex_logged_in:
         print(f"    Error:      {codex_status.get('error')}")
 
+    qwen_logged_in = bool(qwen_status.get("logged_in"))
+    print(
+        f"  {'Qwen OAuth':<12}  {check_mark(qwen_logged_in)} "
+        f"{'logged in' if qwen_logged_in else 'not logged in (run: qwen auth qwen-oauth)'}"
+    )
+    qwen_auth_file = qwen_status.get("auth_file")
+    if qwen_auth_file:
+        print(f"    Auth file:  {qwen_auth_file}")
+    qwen_exp = qwen_status.get("expires_at_ms")
+    if qwen_exp:
+        from datetime import datetime, timezone
+        print(f"    Access exp: {datetime.fromtimestamp(int(qwen_exp) / 1000, tz=timezone.utc).isoformat()}")
+    if qwen_status.get("error") and not qwen_logged_in:
+        print(f"    Error:      {qwen_status.get('error')}")
+
     # =========================================================================
     # Nous Subscription Features
     # =========================================================================