feat: enhance LocalAgent configuration and UI components

- Updated .env.example to provide clearer configuration instructions and API key setup.
- Removed debug_env.py as it was no longer needed.
- Refactored main.py to streamline application initialization and workspace setup.
- Introduced a new HistoryManager for managing task execution history.
- Enhanced UI components in chat_view.py and task_guide_view.py to improve user interaction and code preview functionality.
- Added loading indicators and improved task history display in the UI.
- Implemented unit tests for history management and intent classification.

.env.example

@@ -1,16 +1,19 @@
-# ========================================
-# LocalAgent 閰嶇疆鏂囦欢绀轰緥
 # ========================================
-# 浣跨敤鏂规硶锛?# 1. 澶嶅埗姝ゆ枃浠朵负 .env
-# 2. 濉叆浣犵殑 API Key 鍜屽叾浠栭厤缃?# ========================================
+# LocalAgent Configuration Example
+# ========================================
+# Usage:
+# 1. Copy this file to .env
+# 2. Fill in your API Key and other settings
+# ========================================
 
-# SiliconFlow API 閰嶇疆
-# 鑾峰彇 API Key: https://siliconflow.cn
+# SiliconFlow API Configuration
+# Get API Key: https://siliconflow.cn
 LLM_API_URL=https://api.siliconflow.cn/v1/chat/completions
 LLM_API_KEY=your_api_key_here
 
-# 妯″瀷閰嶇疆
-# 鎰忓浘璇嗗埆妯″瀷锛堟帹鑽愪娇鐢ㄥ皬妯″瀷锛岄€熷害蹇級
+# Model Configuration
+# Intent recognition model (small model recommended for speed)
 INTENT_MODEL_NAME=Qwen/Qwen2.5-7B-Instruct
 
-# 浠ｇ爜鐢熸垚妯″瀷锛堟帹鑽愪娇鐢ㄥぇ妯″瀷锛屾晥鏋滃ソ锛?GENERATION_MODEL_NAME=Qwen/Qwen2.5-72B-Instruct
+# Code generation model (large model recommended for quality)
+GENERATION_MODEL_NAME=Qwen/Qwen2.5-72B-Instruct