[Bug](distinct) Fixes off-by-one error in aggregation limit check

[BiteTheDDDDt]

What problem does this PR solve?

Updates limit condition to ensure exactly the specified number of rows are returned. Prevents exceeding the row limit when the aggregated block reaches or equals the threshold.

Check List (For Author)

• Test

  • Regression test
  • Unit Test
  • Manual test (add detailed scripts or steps below)
  • No need to test or manual test. Explain why:
    • This is a refactor/code format and no logic has been changed.
    • Previous test can cover this change.
    • No code files have been changed.
    • Other reason

• Behavior changed:

  • No.
  • Yes.

• Does this need documentation?

  • No.
  • Yes.

Check List (For Reviewer who merge this PR)

• Confirm the release note
• Confirm test cases
• Confirm document
• Add branch pick label

[hello-stephen]

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Please clearly describe your PR:

1. What problem was fixed (it's best to include specific error reporting information). How it was fixed.
2. Which behaviors were modified. What was the previous behavior, what is it now, why was it modified, and what possible impacts might there be.
3. What features were added. Why was this function added?
4. Which code was refactored and why was this part of the code refactored?
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[BiteTheDDDDt]

run buildall

[Copilot]

Pull request overview

Fixes an off-by-one condition in distinct streaming aggregation to ensure the operator does not emit more than the configured row limit.

Changes:

• Adjusts the limit reach condition from > to >= when evaluating num_rows_returned + aggregated_block->rows()

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[hello-stephen]

BE UT Coverage Report

Increment line coverage 100.00% (1/1) 🎉

Increment coverage report
Complete coverage report

Category	Coverage
Function Coverage	52.52% (19584/37291)
Line Coverage	36.12% (182580/505481)
Region Coverage	32.46% (141686/436531)
Branch Coverage	33.41% (61415/183806)

[hello-stephen]

BE Regression && UT Coverage Report

Increment line coverage 100.00% (1/1) 🎉

Increment coverage report
Complete coverage report

Category	Coverage
Function Coverage	63.14% (23063/36524)
Line Coverage	46.37% (233720/503981)
Region Coverage	43.44% (191425/440699)
Branch Coverage	44.57% (82183/184392)

[hello-stephen]

BE Regression && UT Coverage Report

Increment line coverage 100.00% (1/1) 🎉

Increment coverage report
Complete coverage report

Category	Coverage
Function Coverage	63.14% (23063/36524)
Line Coverage	46.37% (233720/503981)
Region Coverage	43.44% (191425/440699)
Branch Coverage	44.57% (82183/184392)

[hello-stephen]

BE Regression && UT Coverage Report

Increment line coverage 100.00% (1/1) 🎉

Increment coverage report
Complete coverage report

Category	Coverage
Function Coverage	63.27% (23107/36524)
Line Coverage	46.52% (234460/503981)
Region Coverage	43.59% (192093/440699)
Branch Coverage	44.76% (82531/184392)

[HappenLee]

LGTM

[github-actions]

PR approved by at least one committer and no changes requested.

[github-actions]

PR approved by anyone and no changes requested.

[BiteTheDDDDt]

run buildall