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>

.vscode/extensions.json

@@ -0,0 +1,10 @@
+{
+  // 推薦安裝的擴充（可於側邊欄 Extensions 接受建議安裝）
+  "recommendations": [
+    "charliermarsh.ruff",
+    "ms-python.python",
+    "ms-python.vscode-pylance",
+    "ms-toolsai.jupyter",
+    "Natizyskunk.sftp"
+  ]
+}