feat: add progress callback mechanism for real-time updates in data extraction

- Add ProgressInfo and ProgressCalculator classes for structured progress tracking
- Implement RealtimeOutput for immediate log display without buffering
- Add progress callback support to DiscreteMaterialPlanExtractor
- Use queue-based thread-safe communication for GUI progress updates
- Fix log output issue where all content appeared at once after completion

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

gui/utils.py

@@ -0,0 +1,39 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+"""
+GUI 工具模块
+
+提供 GUI 相关的工具类和函数。
+"""
+
+
+class RealtimeOutput:
+    """实时输出流，每次写入立即回调通知"""
+
+    def __init__(self, callback):
+        """
+        初始化实时输出流
+
+        Args:
+            callback: 写入时的回调函数，接收文本内容
+        """
+        self.callback = callback
+        self.buffer = []
+
+    def write(self, text):
+        """写入文本"""
+        if text:
+            # 将文本按行分割，逐行回调
+            lines = text.split('\n')
+            for line in lines:
+                if line:  # 忽略空行（由 split 产生）
+                    self.callback(line)
+        return len(text)
+
+    def flush(self):
+        """刷新（兼容性方法）"""
+        pass
+
+    def isatty(self):
+        """返回 False，表示不是终端"""
+        return False