chore: restore corrupted defaults and add api_key_env

ai/honcho/config.toml

@@ -29,7 +29,7 @@ URL = "redis://honcho-redis:6379/0"
 [llm]
 DEFAULT_MAX_TOKENS = 4096
 
-# Embeddings via Ollama (nomic-embed-text recommended on this system)
+# Embeddings via Ollama
 [embedding]
 VECTOR_DIMENSIONS = 768
 MAX_INPUT_TOKENS = 8192
@@ -39,7 +39,7 @@ transport = "openai"
 model = "nomic-embed-text"
 base_url = "http://ollama:11434/v1"
 
-# --- Deriver (user representation builder) ---
+# --- Deriver ---
 [deriver]
 ENABLED = true
 WORKERS = 1