Let a tooltip linger, and tell the screen reader what it says

A plain tooltip vanished the instant the pointer left, where M3 keeps one for
1.5s and shows only one at a time — these are popover="manual", so nothing was
closing the last one. A rich tooltip's bubble was never associated with its
trigger at all, so the explanation it exists to give was never announced; the
script now writes aria-describedby (and aria-haspopup/aria-expanded when it is
persistent) onto the focusable control in the trigger slot, and again after a
morph. Plan step 18, actions.md ACT-22, ACT-25.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Qwx5USif3wFFmxtHg5U1g9

resources/views/components/tooltip.blade.php

@@ -5,8 +5,9 @@
 
          <x-tooltip text="Copy link"><button …>…</button></x-tooltip>
 
-     It shows after a short hover on a pointer that can hover, at once on keyboard focus, and
-     hides on leave, blur, press and Escape. A phone has no hover, so a control there carries its
+     It shows after a short hover on a pointer that can hover, at once on keyboard focus, and hides
+     at once on a press or Escape; leaving or blurring lets it stand for M3's 1.5s. Only one
+     tooltip is on screen at a time, as M3 asks. A phone has no hover, so a control there carries its
      words. The bubble is a `popover="manual"` in the top layer — never clipped by an
      `overflow-hidden` parent, never widening a scroll container — placed by CSS anchor
      positioning on `side` (`top`, `bottom`, `left`, `right`), flipping when there is no room.