fix(endpoints): normalize URL handling (#4338)

tests/test_endpoint_resolver.py

@@ -1,6 +1,8 @@
 """Tests for endpoint_resolver — pure functions tested directly."""
 import json
 
+import pytest
+
 from src.endpoint_resolver import (
     _first_chat_model,
     _endpoint_hidden_models,
@@ -45,6 +47,9 @@ class TestBuildChatUrl:
     def test_openai_style(self):
         assert build_chat_url("https://api.openai.com/v1") == "https://api.openai.com/v1/chat/completions"
 
+    def test_pathless_openai_style_adds_v1(self):
+        assert build_chat_url("https://api.openai.com") == "https://api.openai.com/v1/chat/completions"
+
     def test_anthropic_style(self):
         assert build_chat_url("https://api.anthropic.com") == "https://api.anthropic.com/v1/messages"
 
@@ -66,14 +71,35 @@ class TestBuildChatUrl:
     def test_ollama_v1_preserves_openai_compat(self):
         assert build_chat_url("http://nas:11434/v1") == "http://nas:11434/v1/chat/completions"
 
+    @pytest.mark.parametrize("bad_base", [
+        "https://api.example.com/v1?token=abc",
+        "https://api.example.com/v1#fragment",
+        "http://localhost:1234?",
+    ])
+    def test_rejects_query_or_fragment_base(self, bad_base):
+        with pytest.raises(ValueError, match="query or fragment"):
+            build_chat_url(bad_base)
+
 
 class TestBuildModelsUrl:
     def test_openai_models(self):
         assert build_models_url("https://api.openai.com/v1") == "https://api.openai.com/v1/models"
 
+    def test_pathless_openai_models_adds_v1(self):
+        assert build_models_url("https://api.openai.com") == "https://api.openai.com/v1/models"
+
     def test_ollama_tags(self):
         assert build_models_url("https://ollama.com/api") == "https://ollama.com/api/tags"
 
+    @pytest.mark.parametrize("bad_base", [
+        "https://api.example.com/v1?token=abc",
+        "https://api.example.com/v1#fragment",
+        "http://localhost:1234?",
+    ])
+    def test_rejects_query_or_fragment_base(self, bad_base):
+        with pytest.raises(ValueError, match="query or fragment"):
+            build_models_url(bad_base)
+
 
 class TestBuildHeaders:
     def test_no_key(self):