Allow drag & drop into open toggle blocks without creating a placeholder block

[expiante]

Dragging and dropping blocks into an open toggle block currently requires creating a placeholder block first, which makes the interaction unintuitive and slower.

Current Behavior

• When a toggle block is open:
  • Drag & drop into it is not possible by default
  • The user must first click “Click to add block” to create a physical empty block
  • Only after that does drag & drop become possible
• When the toggle block is closed, this behavior is acceptable and expected

Expected Behavior

• When a toggle block is open:
  • It should be possible to drag & drop blocks directly into it
  • No need to click Create block or create a placeholder block first
• Drag & drop should work as a direct alternative to creating a new block via the UI

Why This Feature Is Useful

• Makes drag & drop behavior more intuitive and predictable
• Reduces unnecessary steps and placeholder content
• Aligns with the mental model of an “open” container block
• Improves efficiency when reorganizing content

Creating a block should be optional when inserting content via drag & drop, not a prerequisite.

[nperez0111]

Definitely a nice to have feature

[woutervroege]

Similar to #2109