Initial commit: Lunar calendar converter project

- Add lunar calendar astronomical calculation engine (lunar_calendar.py)
- Add converter utilities for solar/lunar date conversion
- Add historical era name conversions (chrono_converter.py, converter_with_eras.py)
- Add FastAPI REST API for date conversion services
- Add age calculator using lunar calendar
- Add batch generation script for lunar calendar JSON data
- Add project documentation (CLAUDE.md, pyproject.toml)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

ruff.toml

@@ -0,0 +1,33 @@
+line-length = 100
+target-version = "py310"
+
+# 忽略常見產物與虛擬環境資料夾
+extend-exclude = [
+  ".venv",
+  "venv",
+  ".tox",
+  ".mypy_cache",
+  ".pytest_cache",
+  ".ruff_cache",
+  "build",
+  "dist",
+  "node_modules",
+]
+
+[lint]
+# 基本錯誤/風格 + 匯入排序 + pyupgrade + bugbear
+select = ["E", "F", "I", "UP", "B"]
+# 允許自動修復所有可修復項目（VS Code 會透過 Code Action 觸發）
+fixable = ["ALL"]
+
+[lint.isort]
+# 預設與 Black 兼容的行為已良好，一般無需額外調整
+
+[format]
+# 格式器偏好（VS Code 也設定了 LF 與 ruler 88）
+quote-style = "double"      # 可選："single" | "double" | "preserve"
+indent-style = "space"      # 可選："space" | "tab"
+line-ending = "lf"          # 可選："lf" | "cr-lf" | "auto"
+# 若文件含有 docstring 內嵌程式碼，可一併格式化
+docstring-code-format = true
+docstring-code-line-length = 100