feat(operator): refuse two hyperparameter rows that set one parameter

[kz930]

What changes were proposed in this PR?

An Advanced trainer emits one keyword argument per row of its Parameter Setting table. Nothing stopped two rows from naming the same parameter, and two rows naming one parameter emitted that keyword twice, which Python rejects while it compiles the operator, before any of it runs. What the user saw was a SyntaxError pointing at a line of generated code rather than at the row they had added.

The row is now refused in two places. In the form, a row whose parameter is already set by another row is marked invalid and says so under the dropdown, alongside the validators the property editor already builds from the schema. The constraint is declared on the field itself, as a uniqueAmongRows key the operator's schema carries, rather than by naming the operator in the frontend, so any repeated section that needs the same rule can ask for it. uniqueItems is not the constraint that was missing: two rows naming one parameter differ in their other fields, so they are distinct items while still colliding on the keyword.

The descriptor refuses the same thing while the workflow compiles. That is what names the operator and the parameter in the error, and it also covers a workflow submitted through the API, which never passes through the form.

Any related issues, documentation, discussions?

Closes #7952

How was this PR tested?

New unit tests on both sides. On the descriptor, two rows naming one parameter must be refused with the parameter named, including the mixed case where one row reads a value and the other reads a column, and two rows naming different parameters must still emit both. On the frontend, the property editor must attach the validator to a field the schema marks unique, reject a value another row already holds, accept one no row holds, and produce the message shown to the user.

The three sklearnAdvanced.base Scala specs pass (17 tests), as does the wider machineLearning package (54 tests), with scalafmtCheckAll and scalafix clean. operator-property-edit-frame.component.spec.ts passes at 237 tests.

I also dumped the generated JSON schema for the SVC trainer to confirm the new key lands on the parameter property next to its enum of parameter names, which is what the frontend reads.

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

Generated-by: Claude Code (Claude Opus 5)

[github-actions]

Automated Reviewer Suggestions

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

• Contributors with relevant context: @carloea2, @Ma77Ball, @mengw15
  You can notify them by mentioning @carloea2, @Ma77Ball, @mengw15 in a comment.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 78.57143% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 93.14%. Comparing base (7fbf64e) to head (496adf4).

Files with missing lines	Patch %	Lines
...it-frame/operator-property-edit-frame.component.ts	75.00%	1 Missing and 1 partial ⚠️
...sklearnAdvanced/base/SklearnAdvancedBaseDesc.scala	83.33%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #7982      +/-   ##
============================================
- Coverage     93.14%   93.14%   -0.01%     
- Complexity     4654     4655       +1     
============================================
  Files          1174     1174              
  Lines         47580    47594      +14     
  Branches       5316     5319       +3     
============================================
+ Hits          44318    44330      +12     
- Misses         1785     1786       +1     
- Partials       1477     1478       +1     

Flag	Coverage Δ		*Carryforward flag
access-control-service	81.00% <ø> (ø)
agent-service	99.32% <ø> (ø)		Carriedforward from 7fbf64e
amber	89.23% <83.33%> (+<0.01%)	⬆️
computing-unit-managing-service	73.67% <ø> (ø)
config-service	86.73% <ø> (ø)
file-service	85.56% <ø> (ø)
frontend	95.64% <75.00%> (-0.01%)	⬇️
notebook-migration-service	79.31% <ø> (ø)
pyamber	97.57% <ø> (ø)		Carriedforward from 7fbf64e
workflow-compiling-service	77.19% <ø> (ø)

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

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[github-actions]

⚠️ Benchmark changes need a look

🟢 4 better · 🔴 1 worse · ⚪ 10 noise (<±5%) · 0 without baseline

Compared against main 7fbf64e 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	424	0.259	24,712/27,558/27,558 us	🟢 -25.5% / 🔴 +126.6%
🟢	bs=100 sw=10 sl=64	945	0.577	105,006/140,386/140,386 us	🟢 -9.5% / 🔴 +53.3%
⚪	bs=1000 sw=10 sl=64	1,117	0.682	891,490/950,868/950,868 us	⚪ within ±5% / 🔴 -8.5%

Baseline details

Latest main 7fbf64e from same runner

config	metric	PR	latest main	7d avg	Δ latest	Δ 7d
bs=10 sw=10 sl=64	throughput	424 tuples/sec	445 tuples/sec	908.02 tuples/sec	-4.7%	-53.3%
bs=10 sw=10 sl=64	MB/s	0.259 MB/s	0.272 MB/s	0.554 MB/s	-4.8%	-53.3%
bs=10 sw=10 sl=64	p50	24,712 us	19,774 us	10,907 us	+25.0%	+126.6%
bs=10 sw=10 sl=64	p95	27,558 us	36,990 us	13,604 us	-25.5%	+102.6%
bs=10 sw=10 sl=64	p99	27,558 us	36,990 us	16,697 us	-25.5%	+65.0%
bs=100 sw=10 sl=64	throughput	945 tuples/sec	957 tuples/sec	1,188 tuples/sec	-1.3%	-20.4%
bs=100 sw=10 sl=64	MB/s	0.577 MB/s	0.584 MB/s	0.725 MB/s	-1.2%	-20.4%
bs=100 sw=10 sl=64	p50	105,006 us	100,625 us	85,003 us	+4.4%	+23.5%
bs=100 sw=10 sl=64	p95	140,386 us	155,161 us	91,599 us	-9.5%	+53.3%
bs=100 sw=10 sl=64	p99	140,386 us	155,161 us	99,202 us	-9.5%	+41.5%
bs=1000 sw=10 sl=64	throughput	1,117 tuples/sec	1,119 tuples/sec	1,221 tuples/sec	-0.2%	-8.5%
bs=1000 sw=10 sl=64	MB/s	0.682 MB/s	0.683 MB/s	0.745 MB/s	-0.1%	-8.5%
bs=1000 sw=10 sl=64	p50	891,490 us	893,439 us	837,593 us	-0.2%	+6.4%
bs=1000 sw=10 sl=64	p95	950,868 us	957,906 us	881,015 us	-0.7%	+7.9%
bs=1000 sw=10 sl=64	p99	950,868 us	957,906 us	915,550 us	-0.7%	+3.9%

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
0,10,10,64,20,471.28,200,128000,424,0.259,24712.42,27557.89,27557.89
1,100,10,64,20,2117.16,2000,1280000,945,0.577,105006.46,140386.10,140386.10
2,1000,10,64,20,17897.97,20000,12800000,1117,0.682,891490.25,950868.03,950868.03

[kz930]

/request-review @aglinxinyuan @carloea2