Update .env.example with all 12 LLM providers + Ollama + TigerGraph

.env.example

@@ -1,19 +1,37 @@
-# Environment variables for GraphRAG Inference Hackathon
-# Copy to .env and fill in your values
+# ═══════════════════════════════════════════════════════════
+# GraphRAG Inference Hackathon — Environment Configuration
+# Supports 12 LLM providers + TigerGraph + Ollama
+# ═══════════════════════════════════════════════════════════
 
-# ──── OpenAI API ────────────────────────────────────
-OPENAI_API_KEY=your-openai-api-key-here
-LLM_MODEL=gpt-4o-mini
-EMBED_MODEL=text-embedding-3-small
+# ──── LLM Providers (set any/all — system auto-detects) ─────
+OPENAI_API_KEY=sk-...
+ANTHROPIC_API_KEY=sk-ant-api03-...
+GEMINI_API_KEY=AIza...
+MISTRAL_API_KEY=...
+COHERE_API_KEY=...
+OPENROUTER_API_KEY=sk-or-v1-...
+GROQ_API_KEY=gsk_...
+XAI_API_KEY=xai-...
+TOGETHER_API_KEY=...
+HF_TOKEN=hf_...
+DEEPSEEK_API_KEY=sk-...
 
-# ──── TigerGraph Cloud ──────────────────────────────
-# Sign up at https://tgcloud.io (free tier available)
+# ──── Ollama (Local — no API key needed) ────────────────────
+# Install: https://ollama.ai
+# Pull models: ollama pull llama3.2
+# Ollama runs on http://localhost:11434 by default
+OLLAMA_BASE_URL=http://localhost:11434
+
+# ──── Default Provider ──────────────────────────────────────
+LLM_PROVIDER=anthropic
+LLM_MODEL=claude-sonnet-4-20250514
+
+# ──── TigerGraph Cloud ──────────────────────────────────────
 TG_HOST=https://YOUR_SUBDOMAIN.tgcloud.io
 TG_GRAPH=GraphRAG
 TG_USERNAME=tigergraph
-TG_PASSWORD=your-tigergraph-password
-TG_TOKEN=
+TG_PASSWORD=
 
-# ──── Dashboard ─────────────────────────────────────
+# ──── Dashboard ─────────────────────────────────────────────
 DASHBOARD_PORT=7860
 DEBUG=false