fix: recognize Conifer as a known provider endpoint (#6429)

* fix: recognize Conifer as a known provider endpoint

Recognize Conifer (api.conifer.build) in providers.js endpoint labels and map conifer.build to the openrouter curation sentinel in routes/model_routes.py so server-returned models are displayed as curated while preserving OpenAI wire compatibility.

Fixes #6205

* test(providers): remove trailing blank line

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Co-authored-by: Alexandre Teixeira <general@alexandreteixeira.dev>

tests/test_provider_classification.py

@@ -45,6 +45,7 @@ class TestDetectProvider:
         ("https://api.openai.com/v1", "openai"),
         ("https://api.x.ai/v1", "openai"),
         ("https://api.deepseek.com", "openai"),
+        ("https://api.conifer.build/v1", "openai"),
         ("https://generativelanguage.googleapis.com/v1beta/openai", "openai"),
         # Ollama's OpenAI-compatible /v1 surface is generic, not native ollama.
         ("http://localhost:11434/v1", "openai"),