Run online, offine chat actor, director tests for any supported provider

- Previously online chat actors, director tests only worked with openai.
  This change allows running them for any supported onlnie provider
  including Google, Anthropic and Openai.

- Enable online/offline chat actor, director in two ways:
  1. Explicitly setting KHOJ_TEST_CHAT_PROVIDER environment variable to
     google, anthropic, openai, offline
  2. Implicitly by the first API key found from openai, google or anthropic.

- Default offline chat provider to use Llama 3.1 3B for faster, lower
  compute test runs

tests/helpers.py

@@ -17,6 +17,32 @@ from khoj.database.models import (
 )
 
 
+def get_chat_provider(default: ChatModelOptions.ModelType | None = ChatModelOptions.ModelType.OFFLINE):
+    provider = os.getenv("KHOJ_TEST_CHAT_PROVIDER")
+    if provider and provider in ChatModelOptions.ModelType:
+        return ChatModelOptions.ModelType(provider)
+    elif os.getenv("OPENAI_API_KEY"):
+        return ChatModelOptions.ModelType.OPENAI
+    elif os.getenv("GEMINI_API_KEY"):
+        return ChatModelOptions.ModelType.GOOGLE
+    elif os.getenv("ANTHROPIC_API_KEY"):
+        return ChatModelOptions.ModelType.ANTHROPIC
+    else:
+        return default
+
+
+def get_chat_api_key(provider: ChatModelOptions.ModelType = None):
+    provider = provider or get_chat_provider()
+    if provider == ChatModelOptions.ModelType.OPENAI:
+        return os.getenv("OPENAI_API_KEY")
+    elif provider == ChatModelOptions.ModelType.GOOGLE:
+        return os.getenv("GEMINI_API_KEY")
+    elif provider == ChatModelOptions.ModelType.ANTHROPIC:
+        return os.getenv("ANTHROPIC_API_KEY")
+    else:
+        return os.getenv("OPENAI_API_KEY") or os.getenv("GEMINI_API_KEY") or os.getenv("ANTHROPIC_API_KEY")
+
+
 class UserFactory(factory.django.DjangoModelFactory):
     class Meta:
         model = KhojUser
@@ -40,19 +66,19 @@ class OpenAIProcessorConversationConfigFactory(factory.django.DjangoModelFactory
     class Meta:
         model = OpenAIProcessorConversationConfig
 
-    api_key = os.getenv("OPENAI_API_KEY")
+    api_key = get_chat_api_key()
 
 
 class ChatModelOptionsFactory(factory.django.DjangoModelFactory):
     class Meta:
         model = ChatModelOptions
 
-    max_prompt_size = 3500
+    max_prompt_size = 20000
     tokenizer = None
-    chat_model = "bartowski/Meta-Llama-3.1-8B-Instruct-GGUF"
-    model_type = "offline"
+    chat_model = "bartowski/Meta-Llama-3.2-3B-Instruct-GGUF"
+    model_type = get_chat_provider()
     openai_config = factory.LazyAttribute(
-        lambda obj: OpenAIProcessorConversationConfigFactory() if os.getenv("OPENAI_API_KEY") else None
+        lambda obj: OpenAIProcessorConversationConfigFactory() if get_chat_api_key() else None
     )