Freeze world input while skill tree console is open

- Add `skillWindow` to the full-screen click guard so clicks don't
  steer the ship or fold panels while the skill tree is open.
- Include the skill window in the shared `_frozen` condition so the
  world parks (throttle/velocity cleared) behind it, matching the
  class console and level-up marquee contract.

js/scenes/GameScene.js

@@ -1988,6 +1988,8 @@ export class GameScene extends Phaser.Scene {
       if (this.questWindow && this.questWindow.isOpen) return;
       // The ship console (depth 80) — the same full-screen contract.
       if (this.shipWindow && this.shipWindow.isOpen) return;
+      // The skill tree console (depth 80) — the same full-screen contract.
+      if (this.skillWindow && this.skillWindow.isOpen) return;
       // Sub-bar OPEN: a click INSIDE it is its own (the panel or one of
       // its buttons — the buttons fire on their own pointerdown). ANY
       // click OUTSIDE — world, deck, HUD, compass — folds it back down
@@ -2765,11 +2767,15 @@ export class GameScene extends Phaser.Scene {
     // The CLASS CONSOLE's freeze (js/ui/ClassWindow.js): picking a class is a
     // decision, not an overlay on top of the fight — the world holds exactly
     // the way it does for a comm's ACK and the level-up marquee.
+    // The SKILL TREE console's freeze (js/ui/SkillWindow.js): ranking skills
+    // and binding seats is a decision the same way — the world holds behind
+    // it (the cabinet idiom), and its clicks never steer the ship.
     const _frozen =
       _commsPaused ||
       this.levelMarquee?.active === true ||
       !!this._jumping ||
-      this.classWindow?.isOpen === true;
+      this.classWindow?.isOpen === true ||
+      this.skillWindow?.isOpen === true;
     // The freeze's PARKING (the ack pause's onPause is the same contract
     // for its own freeze): while ANY freeze holds, the action is parked
     // dead EVERY frame — the ship (target + throttle cleared, velocity