Add MiniMax LLM integration and local .env support

- Add .env to .gitignore (API keys stay local)
- Add LLM client with MiniMax and OpenAI support
- Update config to load from environment variables
- Wire up Architect agent to actually call the LLM
- Add MiniMax API key to local .env file

opus_orchestrator/config.py

@@ -1,10 +1,16 @@
 """Opus Orchestrator AI - Configuration."""
 
+import os
 from pathlib import Path
 from typing import Optional
 from pydantic import BaseModel, Field
 
 
+def _load_env(key: str, default: Optional[str] = None) -> Optional[str]:
+    """Load from environment variable."""
+    return os.environ.get(key, default)
+
+
 class FortressConfig(BaseModel):
     """Configuration for Fortress integration."""
 
@@ -18,10 +24,14 @@ class FortressConfig(BaseModel):
 class AgentConfig(BaseModel):
     """Configuration for AI agents."""
 
-    model: str = Field(default="gpt-4o", description="Default model for agents")
+    model: str = Field(default="MiniMax/MiniMax-M2.1", description="Default model for agents")
     temperature: float = Field(default=0.7, ge=0.0, le=2.0)
     max_tokens: Optional[int] = Field(default=None, description="Max tokens per response")
     max_iterations: int = Field(default=10, description="Max iterations per agent task")
+    
+    # Provider configuration
+    provider: str = Field(default="minimax", description="LLM provider: minimax, openai, anthropic")
+    api_key: Optional[str] = Field(default=None, description="API key for LLM provider")
 
 
 class IterationConfig(BaseModel):
@@ -57,6 +67,37 @@ class OpusConfig(BaseModel):
         frozen = False
 
 
+def load_config_from_env() -> OpusConfig:
+    """Load configuration from environment variables.
+    
+    Reads:
+    - MINIMAX_API_KEY or OPENAI_API_KEY for LLM
+    - GITHUB_TOKEN for GitHub operations
+    """
+    # Load API keys
+    api_key = _load_env("MINIMAX_API_KEY") or _load_env("OPENAI_API_KEY")
+    github_token = _load_env("GITHUB_TOKEN")
+    
+    # Determine provider
+    if _load_env("MINIMAX_API_KEY"):
+        provider = "minimax"
+        default_model = "MiniMax/MiniMax-M2.1"
+    else:
+        provider = "openai"
+        default_model = "gpt-4o"
+    
+    agent_config = AgentConfig(
+        model=default_model,
+        provider=provider,
+        api_key=api_key,
+    )
+    
+    return OpusConfig(
+        agent=agent_config,
+        github_token=github_token,
+    )
+
+
 # Global config instance
 _config: Optional[OpusConfig] = None
 
@@ -65,7 +106,11 @@ def get_config() -> OpusConfig:
     """Get the global configuration instance."""
     global _config
     if _config is None:
-        _config = OpusConfig()
+        # Try to load from environment
+        try:
+            _config = load_config_from_env()
+        except Exception:
+            _config = OpusConfig()
     return _config