Fix .env loading and add debug logging for API key

- Load .env from script directory explicitly
- Add logging to show .env file location and existence
- Show API key preview on startup for debugging

main.py

@@ -7,7 +7,7 @@ with any OpenAI-compatible client (like Open WebUI). Behind the scenes, it:
 1. Detects URLs in user messages and auto-downloads websites
 2. Ingests website content into the RAG knowledge base
 3. Retrieves relevant context from the knowledge base
-4. Passes the enriched context to GLM-4.7-Flash for response generation
+4. Passes the enriched context to OpenRouter for response generation
 
 The user sees a normal chat experience, but the system is actually doing
 sophisticated RAG operations in the background.
@@ -24,10 +24,16 @@ import sys
 import time
 import uuid
 from contextlib import asynccontextmanager
+from pathlib import Path
 from typing import Any, AsyncIterator, Optional
 
-# Load environment variables from .env file
+# Load environment variables from .env file (look in script directory)
 from dotenv import load_dotenv
+SCRIPT_DIR = Path(__file__).parent.resolve()
+ENV_FILE = SCRIPT_DIR / ".env"
+load_dotenv(ENV_FILE)
+
+# Also try loading from current working directory
 load_dotenv()
 
 # Configure logging
@@ -208,11 +214,24 @@ async def lifespan(app: FastAPI):
         state.tool_manager = None
 
     # Initialize OpenRouter client for upstream LLM
+    # Debug: Show .env file status
+    log.info(f"Looking for .env file at: {ENV_FILE}")
+    log.info(f".env file exists: {ENV_FILE.exists()}")
+    
+    api_key = config.OPENROUTER_API_KEY
+    if api_key:
+        key_preview = f"{api_key[:8]}...{api_key[-4:]}" if len(api_key) > 12 else "***"
+        log.info(f"OPENROUTER_API_KEY found: {key_preview}")
+    else:
+        log.warning("OPENROUTER_API_KEY not found in environment!")
+        log.warning(f"Checked .env at: {ENV_FILE}")
+        log.warning("Set OPENROUTER_API_KEY in .env file or as environment variable")
+    
     try:
-        if config.OPENROUTER_API_KEY:
+        if api_key:
             log.info("Initializing OpenRouter client...")
             state.llm_client = AsyncOpenAI(
-                api_key=config.OPENROUTER_API_KEY,
+                api_key=api_key,
                 base_url=config.OPENROUTER_BASE_URL,
             )
             log.info(f"OpenRouter client initialized successfully (model: {config.UPSTREAM_MODEL})")