Moved "architecture" dir to "docs" for clarity

docs/llm_client.md

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+# LLM Client
+
+Hermes Agent uses the OpenAI Python SDK with OpenRouter as the backend, providing access to many models through a single API.
+
+## Configuration
+
+```python
+from openai import OpenAI
+
+client = OpenAI(
+    api_key=os.getenv("OPENROUTER_API_KEY"),
+    base_url="https://openrouter.ai/api/v1"
+)
+```
+
+## Supported Models
+
+Any model available on [OpenRouter](https://openrouter.ai/models):
+
+```python
+# Anthropic
+model = "anthropic/claude-sonnet-4"
+model = "anthropic/claude-opus-4"
+
+# OpenAI
+model = "openai/gpt-4o"
+model = "openai/o1"
+
+# Google
+model = "google/gemini-2.0-flash"
+
+# Open models
+model = "meta-llama/llama-3.3-70b-instruct"
+model = "deepseek/deepseek-chat-v3"
+model = "moonshotai/kimi-k2.5"
+```
+
+## Tool Calling
+
+Standard OpenAI function calling format:
+
+```python
+response = client.chat.completions.create(
+    model=model,
+    messages=messages,
+    tools=[
+        {
+            "type": "function",
+            "function": {
+                "name": "web_search",
+                "description": "Search the web",
+                "parameters": {
+                    "type": "object",
+                    "properties": {
+                        "query": {"type": "string"}
+                    },
+                    "required": ["query"]
+                }
+            }
+        }
+    ],
+)
+
+# Check for tool calls
+if response.choices[0].message.tool_calls:
+    for tool_call in response.choices[0].message.tool_calls:
+        name = tool_call.function.name
+        args = json.loads(tool_call.function.arguments)
+        # Execute tool...
+```
+
+## Reasoning Models
+
+Some models return reasoning/thinking content:
+
+```python
+# Access reasoning if available
+message = response.choices[0].message
+if hasattr(message, 'reasoning_content') and message.reasoning_content:
+    reasoning = message.reasoning_content
+    # Store for trajectory export
+```
+
+## Provider Selection
+
+OpenRouter allows selecting specific providers:
+
+```python
+response = client.chat.completions.create(
+    model=model,
+    messages=messages,
+    extra_body={
+        "provider": {
+            "order": ["Anthropic", "Google"],  # Preferred providers
+            "ignore": ["Novita"],              # Providers to skip
+        }
+    }
+)
+```
+
+## Error Handling
+
+Common errors and handling:
+
+```python
+try:
+    response = client.chat.completions.create(...)
+except openai.RateLimitError:
+    # Back off and retry
+except openai.APIError as e:
+    # Check e.code for specific errors
+    # 400 = bad request (often provider-specific)
+    # 502 = bad gateway (retry with different provider)
+```
+
+## Cost Tracking
+
+OpenRouter returns usage info:
+
+```python
+usage = response.usage
+print(f"Tokens: {usage.prompt_tokens} + {usage.completion_tokens}")
+print(f"Cost: ${usage.cost:.6f}")  # If available
+```