v1.1.0: 增加交互提示、路径输入、窗口属性配置

- main.py: 增加show_banner()启动说明、各阶段[INFO]日志、结果摘要、任意键退出
- file_selector.py: 重写为路径输入→验证→空输入弹窗回退→不存在循环重试
- run.bat: 新建启动脚本(chcp 65001, mode con cols=80 lines=20, color 0B, title固定署名, pause)
- Code/docs/modification-assessment.md: 修改需求评估文档

Releases/v1.0.1/source/utils.py

@@ -0,0 +1,51 @@
+"""Column coordinate conversion utilities."""
+
+
+def col_to_letter(col: int) -> str:
+    """Convert 0-based column index to Excel letter.
+
+    0 → A, 1 → B, ..., 25 → Z, 26 → AA, 27 → AB, ...
+    """
+    result = ''
+    col += 1
+    while col > 0:
+        col -= 1
+        result = chr(col % 26 + ord('A')) + result
+        col //= 26
+    return result
+
+
+def letter_to_col(letter: str) -> int:
+    """Convert Excel column letter to 0-based index.
+
+    A → 0, B → 1, ..., Z → 25, AA → 26, ...
+    """
+    result = 0
+    for ch in letter.upper():
+        result = result * 26 + (ord(ch) - ord('A') + 1)
+    return result - 1
+
+
+def cell_ref_to_rc(ref: str) -> tuple[int, int]:
+    """Convert Excel cell reference (e.g. 'A1', 'BC42') to (row, col).
+
+    Returns 0-based (row, col).
+    """
+    col_letters = []
+    row_digits = []
+    for ch in ref:
+        if ch.isalpha():
+            col_letters.append(ch)
+        else:
+            row_digits.append(ch)
+    col = letter_to_col(''.join(col_letters))
+    row = int(''.join(row_digits)) - 1  # 1-based → 0-based
+    return row, col
+
+
+def rc_to_cell_ref(row: int, col: int) -> str:
+    """Convert 0-based (row, col) to Excel cell reference.
+
+    (0, 0) → 'A1', (1, 2) → 'C2', ...
+    """
+    return col_to_letter(col) + str(row + 1)