release: bump version to 0.58.0

Release 0.58.0 includes the Earth high-precision boundary PMTiles/MVT pipeline, standardized Earth boundary source collectors, China POV boundary configuration templates, and removal of the legacy low-precision GeoJSON fallback. It also adds Earth news target-location queueing/archive support, fixes datasource task status visibility, documents the Earth surface depth-spacing rules that prevent far-zoom z-fighting snow/black blocks, and updates bilingual operations/developer docs.

docs/technical/zh/earth-frontend-context.md

@@ -123,12 +123,16 @@ Browser Camera provider 的手势识别管线在 [motion-browser-provider.js](/h
 
 - [earth.js](/home/ray/dev/linkong/planet/frontend/public/earth/js/earth.js)
 - [terrain.js](/home/ray/dev/linkong/planet/frontend/public/earth/js/terrain.js)
+- [country-boundaries.js](/home/ray/dev/linkong/planet/frontend/public/earth/js/country-boundaries.js)
 
 职责：
 
 - 地球球体、云层、大气
 - 真实地形 mesh
 - terrain tile 拉取、解码、位移、着色
+- 海陆基座与国界底图的整球 overlay
+
+Earth 地表是多层近似同心球，不是单一 mesh。`earth.js` 的基座球、高清材质 overlay、云层/大气，以及 `country-boundaries.js` 的海陆基座都需要明确半径间距。远距视图下 GPU 深度精度会下降，相邻 shell 过近会 z-fighting，表现为黑色闪烁块或雪花。当前稳定策略是让海陆基座使用 `landAltitudeOffset = 0.32`，高清材质使用 `textureOverlayAltitudeOffset = 0.48`；后续新增或调整整球地表 overlay 时，必须同步检查 [Earth 渲染图层顺序](/home/ray/dev/linkong/planet/docs/technical/zh/earth-render-layer-order.md)，并在 50% 缩放视图验证。
 
 ### 7. 图层模块