Add auto-complete flag to LineageEntry

[krishan1390]

Summary

• Adds a new boolean autoCompleteLineageEntry to LineageEntry. Default false preserves the existing client-driven completion semantics (endReplaceSegments).
• When set to true, the entry signals that an observer (e.g. a controller-side periodic task) is permitted to mark the entry completed automatically once all segmentsTo are ONLINE in the external view.
• SegmentLineage serialization is updated to be tolerant on read (accepts both 4-tuple legacy and 5-tuple new format) and conservative on write (emits a 5th element only when the flag is true), so rolling upgrades and mixed-version controllers can co-exist.
• PinotHelixResourceManager's lineage state-transition sites (endReplaceSegments, two branches of revertReplaceSegments) preserve the flag when constructing the updated entry.
• No consumer of the flag is added in this PR — a follow-up will introduce the observer that uses it.

Test plan

• Extended SegmentLineageTest to round-trip a LineageEntry with autoCompleteLineageEntry=true through ZNRecord.
• Added a test that simulates a legacy 4-tuple ZNRecord written by an older controller and asserts it parses with the flag defaulting to false.
• Asserted that two entries differing only in the new flag are not equal.
• Confirmed default-false entries still serialize as 4-tuples (no wire-format churn for existing users).

[codecov-commenter]

Codecov Report

❌ Patch coverage is 76.47059% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 64.27%. Comparing base (0a8ac02) to head (c36f3aa).

Files with missing lines	Patch %	Lines
.../org/apache/pinot/common/lineage/LineageEntry.java	75.00%	1 Missing and 1 partial ⚠️
...rg/apache/pinot/common/lineage/SegmentLineage.java	60.00%	0 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##             master   #18584   +/-   ##
=========================================
  Coverage     64.27%   64.27%           
  Complexity     1137     1137           
=========================================
  Files          3335     3335           
  Lines        205898   205905    +7     
  Branches      32129    32131    +2     
=========================================
+ Hits         132333   132343   +10     
+ Misses        62931    62912   -19     
- Partials      10634    10650   +16     

Flag	Coverage Δ
custom-integration1	100.00% <ø> (ø)
integration	100.00% <ø> (ø)
integration1	100.00% <ø> (ø)
integration2	0.00% <ø> (ø)
java-21	64.27% <76.47%> (+<0.01%)	⬆️
temurin	64.27% <76.47%> (+<0.01%)	⬆️
unittests	64.27% <76.47%> (+<0.01%)	⬆️
unittests1	56.75% <69.23%> (-0.01%)	⬇️
unittests2	36.83% <64.70%> (+<0.01%)	⬆️

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