Improve trash-hover chunk shrink behavior and drag/drop stability

[Siddharth-732]

Fixes #5787

Summary

This PR improves the trash-delete drag UX for block stacks by making delete interactions clearer, safer, and more stable during drag operations.

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What’s Changed

• Added trash-hover visual feedback that smoothly shrinks the actively dragged stack.
• Applied the hover transform only to the currently dragged group so unrelated blocks remain unaffected.
• Made hover enter/exit behavior stable and fully reversible to prevent scale or position drift.

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File Changed

• block.js

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How the Issue Was Solved

• Implemented _setDragGroupTrashHoverScale(...) to manage a reversible hover-shrink state for the active drag group.
• Captured the baseline position and scale once per trash-hover session and reused it to prevent cumulative transform errors.
• Updated the drag-move flow to apply the hover transform after block/group movement in the same frame, avoiding visual misalignment.
• Restricted hover scaling strictly to blocks.dragGroup (the currently dragged stack), ensuring unrelated blocks are unaffected.
• Added drag-state guarding (_dragPointerDown) so transient mouseout events during drag do not trigger drop or delete logic.
• Gated trash deletion logic to occur only on release (pressup) while over the trash area.
• Cleared long-press timeouts during guarded mouseout paths to prevent unintended pie menu activation.

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Video

Music.Blocks.and.4.more.pages.-.Personal.-.Microsoft_.Edge.2026-02-18.19-14-17.mp4

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Result

• Improved precision and confidence when deleting large stacks.
• No accidental deletion while still holding drag.
• No stack fragmentation or persistent shrink after rapid in/out trash hover.

[github-actions]

✅ All Jest tests passed! This PR is ready to merge.

[vanshika2720]

@Siddharth-732 CI check is failing.

[Siddharth-732]

I'll fix it shortly.

[github-actions]

✅ All Jest tests passed! This PR is ready to merge.

[Siddharth-732]

@vanshika2720 Hi, could you please help me with the CI failure?

I haven’t made any dependency-related changes in this PR (only changes in block.js).
To debug the failure, I tried the following:

Verified the PR is opened from my ui branch into sugarlabs:master.

Synced my branch with the latest upstream/master (it was already up to date).

Confirmed that package.json was not modified by my changes.

Tried reinstalling dependencies locally using npm install.

[github-actions]

✅ All Jest tests passed! This PR is ready to merge.

[subhraneel2005]

@Siddharth-732 try changeing "electron-builder" version to "26.7.0" both in package.json and package-lock.json

[vanshika2720]

@Siddharth-732 I think you got your answer...and if you have any other confusion/or need help please let me know.

[subhraneel2005]

@Siddharth-732 bro take pull from latest commit and re run ci, it should work now :)

[github-actions]

✅ All Jest tests passed! This PR is ready to merge.

[Siddharth-732]

Finally !
@vanshika2720 @subhraneel2005 thanks a lot guys.

[Siddharth-732]

@walterbender @omsuneri please review this, let me know if any changes are required.

[Ashutoshx7]

@Siddharth-732 hy siddhart this can be good addition
but still if possible join sugarlabs meeting 5:30 pm sunday
mentors opinion is necessary as they can instruct you better on this

[Siddharth-732]

Meet will be on next Sunday right ?

[Ashutoshx7]

Meet will be on next Sunday right ?

yes