fix: refine earth hud structure and bun startup flow

- refactor the /earth HUD into class-first CSS layers with dedicated base, hud, and toolbar responsibilities
- clean up Earth markup and runtime DOM hooks so shared panel, toolbar, tooltip, and status classes stay consistent after dynamic updates
- keep HUD scaling configurable through extracted constants and remove leftover legacy panel/toolbar styling paths
- make planet.sh self-bootstrap Bun and uv by prepending local runtime bins to PATH and auto-installing missing tools in fresh environments
- document Bun as the frontend package manager of record and sync repository version metadata to 0.24.1

frontend/public/earth/js/controls.js

@@ -76,7 +76,7 @@ function setFloatingMenuOpen(group, shouldOpen) {
 }
 
 function setButtonTooltip(button, text) {
-  const tooltip = button?.querySelector(".tooltip");
+  const tooltip = button?.querySelector(".earth-toolbar-tooltip");
   if (tooltip) {
     tooltip.textContent = text;
   }
@@ -566,7 +566,7 @@ function updateRotateUI() {
   if (btn) {
     btn.classList.toggle("active", autoRotate);
     btn.classList.toggle("is-stopped", !autoRotate);
-    const tooltip = btn.querySelector(".tooltip");
+    const tooltip = btn.querySelector(".earth-toolbar-tooltip");
     if (tooltip) tooltip.textContent = autoRotate ? "暂停旋转" : "开始旋转";
   }
 }
@@ -599,7 +599,7 @@ function updateLayoutUI(container) {
   const btn = document.getElementById("layout-toggle");
   if (btn) {
     btn.classList.toggle("active", layoutExpanded);
-    const tooltip = btn.querySelector(".tooltip");
+    const tooltip = btn.querySelector(".earth-toolbar-tooltip");
     const nextLabel = layoutExpanded ? "恢复布局" : "最大化布局";
     btn.title = nextLabel;
     if (tooltip) tooltip.textContent = nextLabel;