Batch canvas rendering using stageDirty flag to reduce redundant stage.update() calls

[stutijain2006]

This PR improves runtime rendering efficiency by reducing unnecessary stage.update() calls and switching to a batched rendering approach using a stageDirty flag.

Instead of triggering immediate canvas redraws from multiple event handlers (keyboard movement, resizing, idle wake-up, scrolling, etc.), we now:

• Mark the stage as dirty (stageDirty = true)
• Allow the centralized render loop to perform the actual stage.update() once per frame

This avoids redundant synchronous canvas redraws and reduces scripting overhead on the main thread.

Changes made -
Replaced direct stage.update() calls with stageDirty = true in:

• _doLargerBlocks()
• _doSmallerBlocks()
• resetIdleTimer()
• Multiple branches inside __keyPressed()

This ensures one canvas redraw per frame and no redundant forced synchronous updates.

Performance Changes -
This is a runtime efficiency optimization, not a Lighthouse score booster.

Before-

• 1st party main thread time: ~300 ms
• Total scripting time: ~635 ms
• Total timeline window: ~12.1 s

After-

• 1st party main thread time: ~182 ms
• Total scripting time: ~469 ms
• Total timeline window: ~10.2 s

Result-

• ~26% reduction in main-thread time (1st party)
• ~160 ms reduction in scripting work
• Fewer forced synchronous canvas redraws

Functional Verification-
All core interactions were manually tested:

• Block movement via keyboard
• Palette scrolling
• Block resizing
• Play / Stop
• Idle wake-up behavior
  All functionality remains unchanged.

[github-actions]

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

[omsuneri]

@stutijain2006 please resolve the linting issue

[github-actions]

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

[stutijain2006]

@stutijain2006 please resolve the linting issue

I even did forced formatting now so that the lint error doesn't appear, but don't know why it is coming, can you guide me for the same ?

[kartikktripathi]

This might be because of different prettier versions used by your locals and by musicblocks. Please check the same and commit again. I believe that will solve the issue.

[github-actions]

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

[stutijain2006]

@walterbender This PR is ready for review and merge , please see to it.