feat(pyamber): validate executor definitions

[carloea2]

What changes were proposed in this PR?

Replace the removable assert on executor definition count with an explicit ValueError.

The regression covers both missing and multiple operator definitions under normal and optimized Python.

Any related issues, documentation, discussions?

Closes #8207

How was this PR tested?

python -c "import sys,pytest; sys.path[:0]=[r'<worktree>ambersrcmainpython',r'<main-checkout>ambersrcmainpython']; raise SystemExit(pytest.main([r'amber/src/test/python/core/architecture/managers/test_executor_manager.py','-q','-p','no:cacheprovider']))"
25 passed

python -O -c "import sys,pytest; sys.path[:0]=[r'<worktree>ambersrcmainpython',r'<main-checkout>ambersrcmainpython']; raise SystemExit(pytest.main([r'amber/src/test/python/core/architecture/managers/test_executor_manager.py','-q','-p','no:cacheprovider','-k','no_operator_class_is_rejected or multiple_operator_classes_is_rejected']))"
2 passed

ruff check amber/src/main/python amber/src/test/python
All checks passed

ruff format --check amber/src/main/python amber/src/test/python
213 files already formatted

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

Generated-by: Codex

[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/managers/executor_manager.py, amber/src/test/python/core/architecture/managers/test_executor_manager.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	Change detected on this branch — label added; this fix is queued to backport here. Requested review from @xuang7.

Auto-label run.

[github-actions]

Automated Reviewer Suggestions

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

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

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.90%. Comparing base (70c2114) to head (3a8953f).

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #8208      +/-   ##
============================================
- Coverage     93.94%   93.90%   -0.04%     
  Complexity     4759     4759              
============================================
  Files          1185     1185              
  Lines         48069    48813     +744     
  Branches       5359     5359              
============================================
+ Hits          45159    45840     +681     
- Misses         1480     1543      +63     
  Partials       1430     1430              

Flag	Coverage Δ		*Carryforward flag
access-control-service	81.00% <ø> (ø)		Carriedforward from 70c2114
agent-service	99.32% <ø> (ø)		Carriedforward from 70c2114
amber	89.99% <ø> (ø)		Carriedforward from 70c2114
computing-unit-managing-service	73.67% <ø> (ø)		Carriedforward from 70c2114
config-service	86.86% <ø> (ø)		Carriedforward from 70c2114
file-service	87.91% <ø> (ø)		Carriedforward from 70c2114
frontend	96.49% <ø> (ø)		Carriedforward from 70c2114
notebook-migration-service	79.31% <ø> (ø)		Carriedforward from 70c2114
pyamber	97.85% <100.00%> (-1.02%)	⬇️
workflow-compiling-service	77.19% <ø> (ø)		Carriedforward from 70c2114

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

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[github-actions]

⚠️ Benchmark changes need a look

🟢 7 better · 🔴 1 worse · ⚪ 7 noise (<±5%) · 0 without baseline

Compared against main 70c2114 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	393	0.24	24,150/37,115/37,115 us	🟢 -29.9% / 🔴 +138.2%
🔴	bs=100 sw=10 sl=64	813	0.496	122,389/137,692/137,692 us	🟢 -7.7% / 🔴 +28.4%
⚪	bs=1000 sw=10 sl=64	933	0.57	1,074,661/1,133,999/1,133,999 us	⚪ within ±5% / 🔴 +10.8%

Baseline details

Latest main 70c2114 from same runner

config	metric	PR	latest main	7d avg	Δ latest	Δ 7d
bs=10 sw=10 sl=64	throughput	393 tuples/sec	337 tuples/sec	787.98 tuples/sec	+16.6%	-50.1%
bs=10 sw=10 sl=64	MB/s	0.24 MB/s	0.206 MB/s	0.481 MB/s	+16.5%	-50.1%
bs=10 sw=10 sl=64	p50	24,150 us	29,051 us	12,593 us	-16.9%	+91.8%
bs=10 sw=10 sl=64	p95	37,115 us	52,929 us	15,579 us	-29.9%	+138.2%
bs=10 sw=10 sl=64	p99	37,115 us	52,929 us	18,786 us	-29.9%	+97.6%
bs=100 sw=10 sl=64	throughput	813 tuples/sec	841 tuples/sec	1,008 tuples/sec	-3.3%	-19.3%
bs=100 sw=10 sl=64	MB/s	0.496 MB/s	0.514 MB/s	0.615 MB/s	-3.5%	-19.4%
bs=100 sw=10 sl=64	p50	122,389 us	114,418 us	100,701 us	+7.0%	+21.5%
bs=100 sw=10 sl=64	p95	137,692 us	149,121 us	107,244 us	-7.7%	+28.4%
bs=100 sw=10 sl=64	p99	137,692 us	149,121 us	116,122 us	-7.7%	+18.6%
bs=1000 sw=10 sl=64	throughput	933 tuples/sec	942 tuples/sec	1,042 tuples/sec	-1.0%	-10.5%
bs=1000 sw=10 sl=64	MB/s	0.57 MB/s	0.575 MB/s	0.636 MB/s	-0.9%	-10.4%
bs=1000 sw=10 sl=64	p50	1,074,661 us	1,055,322 us	981,959 us	+1.8%	+9.4%
bs=1000 sw=10 sl=64	p95	1,133,999 us	1,119,720 us	1,023,080 us	+1.3%	+10.8%
bs=1000 sw=10 sl=64	p99	1,133,999 us	1,119,720 us	1,051,697 us	+1.3%	+7.8%

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
0,10,10,64,20,508.39,200,128000,393,0.240,24150.14,37115.06,37115.06
1,100,10,64,20,2459.65,2000,1280000,813,0.496,122388.85,137692.17,137692.17
2,1000,10,64,20,21426.67,20000,12800000,933,0.570,1074660.61,1133998.65,1133998.65