fix: reposition popover after picker opens, debounce popup saves

- Popover: call positionPopover() after opening the picker so the
  popover flips above the badge if it would clip the viewport bottom.
- Popup: debounce saveFromControls() calls during picker drag (200ms)
  to avoid dozens of storage writes per gesture.

Co-authored-by: Cursor <cursoragent@cursor.com>

content/tweaks/color-popover.js

@@ -161,6 +161,7 @@
       row.hex.classList.remove("rt-input-error");
       updatePreview();
     });
+    if (currentAnchor) positionPopover(currentAnchor);
   }
 
   function closePicker() {