feat(pyamber): preserve minus-one shuffle hashes

[carloea2]

What changes were proposed in this PR?

Hash shuffle now uses the tuple's raw Java-compatible hash method directly, avoiding Python's reserved -1 to -2 normalization before receiver selection.

Any related issues, documentation, discussions?

Closes #8253

How was this PR tested?

Retested with Python 3.12 on Windows in a fresh detached worktree from upstream main at 7426431337, which includes the merged loop-completion change #8938. Regression before implementation: 1 failed, 37 passed. After implementation: 38 passed.

The raw-hash change now lives in the shared partitioner's routing override.

Generate protobufs with bash bin/python-proto-gen.sh, then run from amber:

python -m pytest src/test/python/core/architecture/sendsemantics/test_partitioners.py -q --tb=line -p no:cacheprovider
python -m ruff check src/main/python src/test/python
python -m ruff format --check src/main/python src/test/python

Ruff lint and formatting pass for all 217 Python files.

Was this PR authored or co-authored using generative AI tooling?

Generated-by: Codex

[github-actions]

Automated Reviewer Suggestions

Based on the git blame history of the changed files, we recommend the following reviewers:

• Contributors with relevant context: @Ma77Ball
  You can notify them by mentioning @Ma77Ball in a comment.

[github-actions]

Backport auto-label report

This fix: PR was checked against each actively-supported release branch. release/* labels drive the post-merge backport, so add or remove one to change where this fix lands.

Release branch	Analysis
⚠️ release/v1.3	Not labeled automatically — none of the files this PR modifies exist on this branch (amber/src/main/python/core/architecture/sendsemantics/hash_based_shuffle_partitioner.py, amber/src/test/python/core/architecture/sendsemantics/test_partitioners.py). The fix may target code that isn't on this release, or the files were moved/renamed after the branch was cut. Please check and add release/v1.3 by hand if this fix should be backported here.
✅ release/v1.2	Already labeled — this fix is queued to backport here.

Auto-label run.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.30%. Comparing base (7426431) to head (99fd075).

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #8254      +/-   ##
============================================
- Coverage     92.30%   92.30%   -0.01%     
  Complexity     5046     5046              
============================================
  Files          1260     1260              
  Lines         53887    53887              
  Branches       6711     6711              
============================================
- Hits          49743    49740       -3     
- Misses         2486     2488       +2     
- Partials       1658     1659       +1     

Flag	Coverage Δ		*Carryforward flag
access-control-service	77.38% <ø> (ø)		Carriedforward from 7426431
agent-service	99.16% <ø> (ø)		Carriedforward from 7426431
amber	87.32% <ø> (ø)		Carriedforward from 7426431
computing-unit-managing-service	60.48% <ø> (ø)		Carriedforward from 7426431
config-service	87.37% <ø> (ø)		Carriedforward from 7426431
file-service	82.00% <ø> (ø)		Carriedforward from 7426431
frontend	96.55% <ø> (ø)		Carriedforward from 7426431
notebook-migration-service	83.73% <ø> (ø)		Carriedforward from 7426431
pyamber	98.47% <100.00%> (-0.07%)	⬇️
workflow-compiling-service	72.43% <ø> (ø)		Carriedforward from 7426431

*This pull request uses carry forward flags. Click here to find out more.

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[github-actions]

⚠️ Benchmark changes need a look

🟢 2 better · 🔴 4 worse · ⚪ 9 noise (<±5%) · 0 without baseline

Compared against main 7426431 benchmarked on this same runner, so the delta is largely free of cross-runner hardware noise. The "7d avg" column still reflects the gh-pages dashboard. Treat <±5% as noise unless repeated.

Dashboard · Run

	config	throughput	MB/s	latency	max Δ latest / 7d
🔴	bs=10 sw=10 sl=64	524	0.32	18,348/25,451/25,451 us	🟢 -19.0% / 🔴 +64.5%
🔴	bs=100 sw=10 sl=64	1,170	0.714	83,268/123,002/123,002 us	🔴 +5.8% / 🔴 +18.1%
🔴	bs=1000 sw=10 sl=64	1,427	0.871	697,672/798,666/798,666 us	🔴 +6.6% / 🟢 +29.9%

Baseline details

Latest main 7426431 from same runner

config	metric	PR	latest main	7d avg	Δ latest	Δ 7d
bs=10 sw=10 sl=64	throughput	524 tuples/sec	543 tuples/sec	822.11 tuples/sec	-3.5%	-36.3%
bs=10 sw=10 sl=64	MB/s	0.32 MB/s	0.331 MB/s	0.502 MB/s	-3.3%	-36.2%
bs=10 sw=10 sl=64	p50	18,348 us	15,923 us	12,129 us	+15.2%	+51.3%
bs=10 sw=10 sl=64	p95	25,451 us	31,422 us	15,469 us	-19.0%	+64.5%
bs=10 sw=10 sl=64	p99	25,451 us	31,422 us	18,357 us	-19.0%	+38.6%
bs=100 sw=10 sl=64	throughput	1,170 tuples/sec	1,193 tuples/sec	1,058 tuples/sec	-1.9%	+10.6%
bs=100 sw=10 sl=64	MB/s	0.714 MB/s	0.728 MB/s	0.646 MB/s	-1.9%	+10.6%
bs=100 sw=10 sl=64	p50	83,268 us	78,730 us	97,399 us	+5.8%	-14.5%
bs=100 sw=10 sl=64	p95	123,002 us	129,164 us	104,184 us	-4.8%	+18.1%
bs=100 sw=10 sl=64	p99	123,002 us	129,164 us	117,615 us	-4.8%	+4.6%
bs=1000 sw=10 sl=64	throughput	1,427 tuples/sec	1,413 tuples/sec	1,099 tuples/sec	+1.0%	+29.9%
bs=1000 sw=10 sl=64	MB/s	0.871 MB/s	0.862 MB/s	0.671 MB/s	+1.0%	+29.9%
bs=1000 sw=10 sl=64	p50	697,672 us	703,582 us	946,743 us	-0.8%	-26.3%
bs=1000 sw=10 sl=64	p95	798,666 us	749,116 us	985,437 us	+6.6%	-19.0%
bs=1000 sw=10 sl=64	p99	798,666 us	749,116 us	1,012,622 us	+6.6%	-21.1%

Raw CSV

config_idx,batch_size,schema_width,string_len,num_batches,total_ms,total_tuples,total_bytes,tuples_per_sec,mb_per_sec,lat_p50_us,lat_p95_us,lat_p99_us
0,10,10,64,20,381.63,200,128000,524,0.320,18347.78,25450.77,25450.77
1,100,10,64,20,1709.94,2000,1280000,1170,0.714,83267.69,123002.19,123002.19
2,1000,10,64,20,14012.23,20000,12800000,1427,0.871,697671.85,798666.35,798666.35

[Yicong-Huang]

I am converting this PR to a draft: please follow our PR template and mark it ready for review.

[carloea2]

The description now follows the current template, and this is ready for review.