feat: 完善文字画视觉并新增 PDF 导出

- 调整飞鸟、楼群与标题配色和布局
- 新增 uv + Playwright PDF 导出脚本，四边各留 1em
- 页面标题改为「封面」

pyproject.toml

@@ -0,0 +1,11 @@
+[project]
+name = "juazi-gala"
+version = "0.1.0"
+description = "落日文字画页面与 PDF 导出工具"
+requires-python = ">=3.10"
+dependencies = [
+    "playwright>=1.48",
+]
+
+[tool.uv]
+package = false