chore: add .env.example for project setup

.env.example

@@ -0,0 +1,20 @@
+# InkOS Environment Configuration
+# Copy to .env and fill in your values
+
+# LLM Provider (openai, anthropic, custom)
+INKOS_LLM_PROVIDER=openai
+
+# API Base URL (OpenAI-compatible endpoint)
+INKOS_LLM_BASE_URL=https://api.openai.com/v1
+
+# API Key
+INKOS_LLM_API_KEY=sk-your-key-here
+
+# Model name
+INKOS_LLM_MODEL=gpt-4o
+
+# Notifications (optional)
+INKOS_TELEGRAM_BOT_TOKEN=
+INKOS_TELEGRAM_CHAT_ID=
+INKOS_FEISHU_WEBHOOK_URL=
+INKOS_WECOM_WEBHOOK_URL=