feat: aider multi-provider credentials + test suite green (182/182)

aider_run multi-provider credentials (tools/aider.py):
- _resolve_credentials() — general credential resolver; replaces the previous
  OpenRouter-only injection; resolution priority: Anthropic model hint → explicit
  host_label → model prefix (openrouter/*, groq/*, deepseek/*, …) → OpenRouter
  default → Anthropic API key → any keyed cloud host → local/generic host
- _host_flags() — generates --api-key slug=key for known cloud providers (OpenRouter,
  OpenAI, Groq, Together, Fireworks, X.ai, DeepSeek, Mistral); generates
  --openai-api-base + --openai-api-key for generic/local hosts (Open WebUI, Ollama);
  appends /api suffix for openwebui host_type; auto-prefixes model with 'openai/'
  for generic endpoints when model has no / prefix
- Anthropic API keys from providers.anthropic.credentials (not a host entry)
- host_label param added to aider_run and FunctionDeclaration — pick a configured
  host by partial label match (e.g. 'OpenRouter', 'Local', 'scott-lt-i7-rtx')
- 16 unit tests for _resolve_credentials covering all resolution paths

main.py: move @app.get("/health") before app.include_router(ui.router) — the
/{username} catch-all in ui.router was swallowing the /health path

Test suite: 37 pre-existing failures → 182/182 passing
- test_tools.py: _task_list() missing priority arg (6 callsites); cron ID regex
  c_\w+ → c_[\w-]+ (token_urlsafe includes '-', causing intermittent truncation)
- test_webhooks.py: rewritten for per-user channel config architecture —
  patch routers.nextcloud_talk/google_chat.get_user_channels instead of removed
  settings fields; corrected endpoints /webhook/nextcloud/scott and
  /channels/google-chat/scott; non-empty cfg dicts so falsy-guard passes
- test_health.py: test_unknown_route_404 now uses 3-segment path (/{u}/{p}/x)
  since single-segment paths hit the /{username} UI catch-all
- test_api_files.py: removed '../config.py' from not-in-allowed test (ASGI
  normalizes it to /config.py which hits /{username} catch-all, not files router)
- test_security.py: same webhook patch target fix; per-user endpoint URLs

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

cortex/tests/test_security.py

@@ -69,10 +69,11 @@ async def test_nct_replayed_request_rejected(client):
     payload = json.dumps({"type": "Create", "actor": {}, "object": {}, "target": {}}).encode()
     # Use wrong secret to generate sig
     wrong_sig = hmac_lib.new(b"wrong-secret", b"abc123" + payload, hashlib.sha256).hexdigest()
+    _channels = {"nextcloud": {"bot_secret": "correct-secret", "url": "https://nc.example.com"}}
     from unittest.mock import patch
-    with patch("config.settings.nextcloud_talk_bot_secret", "correct-secret"):
+    with patch("routers.nextcloud_talk.get_user_channels", return_value=_channels):
         r = await client.post(
-            "/inara-nextcloud-talk-webhook",
+            "/webhook/nextcloud/scott",
             content=payload,
             headers={
                 "Content-Type": "application/json",
@@ -118,9 +119,11 @@ async def test_known_gap__gchat_no_audience_bypass(client, mock_llm):
     LLM responses without a valid token.
     Fix: make audience required; fail loudly if not set.
     """
+    # Channel config with no audience — JWT check is skipped (the known gap).
+    _channels = {"google_chat": {"persona": "inara"}}
     from unittest.mock import patch
-    with patch("config.settings.google_chat_audience", ""):
-        r = await client.post("/channels/google-chat", json={
+    with patch("routers.google_chat.get_user_channels", return_value=_channels):
+        r = await client.post("/channels/google-chat/scott", json={
             "chat": {
                 "messagePayload": {
                     "message": {"text": "Exploit"},