fix(llms,embeddings): repair HTTP proxy support (httpx>=0.28) and preserve proxies in LlmFactory (#5447)

Co-authored-by: kartik-mem0 <kartik.labhshetwar@mem0.ai>

tests/test_http_client_proxies.py

@@ -0,0 +1,39 @@
+import httpx
+import pytest
+
+from mem0.configs.embeddings.base import BaseEmbedderConfig
+from mem0.configs.llms.base import BaseLlmConfig
+from mem0.utils.factory import LlmFactory
+
+
+@pytest.mark.parametrize("config_cls", [BaseLlmConfig, BaseEmbedderConfig])
+def test_config_with_string_proxy_builds_client(config_cls):
+    config = config_cls(http_client_proxies="http://proxy.local:8080")
+    assert isinstance(config.http_client, httpx.Client)
+    assert config.http_client_proxies == "http://proxy.local:8080"
+
+
+@pytest.mark.parametrize("config_cls", [BaseLlmConfig, BaseEmbedderConfig])
+def test_config_with_dict_proxy_builds_client(config_cls):
+    proxies = {"http://": "http://p:8080", "https://": "http://p:8080"}
+    config = config_cls(http_client_proxies=proxies)
+    assert isinstance(config.http_client, httpx.Client)
+    assert config.http_client_proxies == proxies
+
+
+@pytest.mark.parametrize("config_cls", [BaseLlmConfig, BaseEmbedderConfig])
+def test_config_without_proxy_has_no_client(config_cls):
+    config = config_cls()
+    assert config.http_client is None
+    assert config.http_client_proxies is None
+
+
+def test_llm_factory_preserves_http_client_proxies():
+    base = BaseLlmConfig(
+        model="gpt-4o-mini",
+        api_key="sk-test",
+        http_client_proxies="http://proxy.local:8080",
+    )
+    llm = LlmFactory.create("openai", base)
+    assert llm.config.http_client_proxies == "http://proxy.local:8080"
+    assert isinstance(llm.config.http_client, httpx.Client)