fix: redesign earth hud interactions and legend behavior

docs/CHANGELOG.md

@@ -7,6 +7,35 @@ This project follows the repository versioning rule:
 - `feature` -> `+0.1.0`
 - `bugfix` -> `+0.0.1`
 
+## 0.21.2
+
+Released: 2026-03-26
+
+### Highlights
+
+- Reworked the Earth page HUD into a bottom-centered floating toolbar with grouped popovers and richer interaction feedback.
+- Unified toolbar and corner cards under a liquid-glass visual language and refined status toasts, object info cards, and legend behavior.
+- Made the legend state reflect the currently selected Earth object instead of a fixed static list.
+
+### Added
+
+- Added a reusable Earth legend module in [legend.js](/home/ray/dev/linkong/planet/frontend/public/earth/js/legend.js).
+- Added Material Symbols-based Earth toolbar icons and dedicated fullscreen-collapse icon support.
+- Added click-to-copy support for info-card field labels.
+
+### Improved
+
+- Improved Earth toolbar layout with centered floating controls, popover-based display toggles, and zoom controls.
+- Improved Earth HUD visuals with liquid-glass styling for buttons, info cards, panels, and animated status messages.
+- Improved info-card spacing, scrollbar styling, and object detail readability.
+- Improved legend rendering so cable and satellite object selection can drive the displayed legend content.
+
+### Fixed
+
+- Fixed tooltip coverage and splash copy mismatches in the Earth page controls.
+- Fixed several toolbar icon clarity, centering, and state-toggle issues.
+- Fixed status-message behavior so repeated notifications replay the slide-in animation.
+
 ## 0.20.0
 
 Released: 2026-03-26