feat(workflow-operator): stop forcing a color column on every Bubble Chart

[kz930]

What changes were proposed in this PR?

Bubble Chart's Color-Column was declared required = true with @NotNull, but the generated Python reads it only inside the Enable Color branch. The effect was that a freshly dropped Bubble Chart stayed invalid until the user picked a color column, even when they wanted plain bubbles — and the column they picked was then never used.

This PR makes the field optional and puts it behind the toggle via toggleHidden, so it disappears from the panel when Enable Color is off. That matches Ternary Plot, which has the same toggle-plus-column pair and already declares its color field optional.

The color decision also moves out of the generated Python and into Scala. The old template emitted an if '...' == 'true': comparison over a Scala Boolean; it is now a colorArg computed at build time, guarded on both the toggle and the column being non-empty. That second half matters: with the required flag gone, an empty column would otherwise reach px.scatter(color=''), which plotly rejects — the same failure fixed for Bar Chart in #6792.

Behavior for existing workflows is unchanged. enableColor keeps its meaning, so no saved chart changes appearance.

The operator reference page is updated to match the new requirement and description.

Any related issues, documentation, discussions?

Closes #7395

How was this PR tested?

Existing BubbleChartOpDescSpec passes unchanged, including the assertion that pins the no-color output line. Three cases were added to it, covering the toggle-and-column matrix: enabled with a column chosen (color is emitted), enabled with no column (color is omitted rather than emitted empty), and disabled with a column chosen (the column is not emitted).

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

Generated-by: Claude Code (Claude Opus 5)

[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/v1.2	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:

• Committers with relevant context: @parshimers
  You can request their reviews formally with /request-review @parshimers.

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

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 83.26%. Comparing base (e7cd5b1) to head (6e35895).
⚠️ Report is 60 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #7396      +/-   ##
============================================
+ Coverage     82.73%   83.26%   +0.53%     
- Complexity     4089     4151      +62     
============================================
  Files          1162     1164       +2     
  Lines         46302    46419     +117     
  Branches       5162     5172      +10     
============================================
+ Hits          38308    38652     +344     
+ Misses         6302     6041     -261     
- Partials       1692     1726      +34     

Flag	Coverage Δ		*Carryforward flag
access-control-service	70.00% <ø> (ø)
agent-service	83.65% <ø> (ø)		Carriedforward from e7cd5b1
amber	80.83% <100.00%> (+1.30%)	⬆️
computing-unit-managing-service	50.72% <ø> (+7.11%)	⬆️
config-service	65.97% <ø> (ø)
file-service	69.05% <ø> (+1.31%)	⬆️
frontend	83.55% <ø> (ø)		Carriedforward from e7cd5b1
notebook-migration-service	78.89% <ø> (ø)
pyamber	97.36% <ø> (ø)		Carriedforward from e7cd5b1
workflow-compiling-service	26.31% <ø> (ø)

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

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[kz930]

@carloea2 May you take a look at this?

[github-actions]

⚠️ Benchmark changes need a look

🟢 2 better · 🔴 10 worse · ⚪ 3 noise (<±5%) · 0 without baseline

Compared against main 5e41efa 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	398	0.243	23,777/32,124/32,124 us	🔴 +7.7% / 🔴 +98.8%
🔴	bs=100 sw=10 sl=64	897	0.547	109,591/158,102/158,102 us	🔴 +19.6% / 🔴 +42.6%
🔴	bs=1000 sw=10 sl=64	1,091	0.666	907,890/1,073,753/1,073,753 us	🔴 +10.9% / 🟢 -11.1%

Baseline details

Latest main 5e41efa from same runner

config	metric	PR	latest main	7d avg	Δ latest	Δ 7d
bs=10 sw=10 sl=64	throughput	398 tuples/sec	429 tuples/sec	755.31 tuples/sec	-7.2%	-47.3%
bs=10 sw=10 sl=64	MB/s	0.243 MB/s	0.262 MB/s	0.461 MB/s	-7.3%	-47.3%
bs=10 sw=10 sl=64	p50	23,777 us	22,068 us	12,952 us	+7.7%	+83.6%
bs=10 sw=10 sl=64	p95	32,124 us	34,585 us	16,161 us	-7.1%	+98.8%
bs=10 sw=10 sl=64	p99	32,124 us	34,585 us	19,292 us	-7.1%	+66.5%
bs=100 sw=10 sl=64	throughput	897 tuples/sec	984 tuples/sec	957.58 tuples/sec	-8.8%	-6.3%
bs=100 sw=10 sl=64	MB/s	0.547 MB/s	0.6 MB/s	0.584 MB/s	-8.8%	-6.4%
bs=100 sw=10 sl=64	p50	109,591 us	99,326 us	104,473 us	+10.3%	+4.9%
bs=100 sw=10 sl=64	p95	158,102 us	132,174 us	110,867 us	+19.6%	+42.6%
bs=100 sw=10 sl=64	p99	158,102 us	132,174 us	120,336 us	+19.6%	+31.4%
bs=1000 sw=10 sl=64	throughput	1,091 tuples/sec	1,084 tuples/sec	986.93 tuples/sec	+0.6%	+10.5%
bs=1000 sw=10 sl=64	MB/s	0.666 MB/s	0.661 MB/s	0.602 MB/s	+0.8%	+10.6%
bs=1000 sw=10 sl=64	p50	907,890 us	923,594 us	1,021,008 us	-1.7%	-11.1%
bs=1000 sw=10 sl=64	p95	1,073,753 us	968,353 us	1,059,187 us	+10.9%	+1.4%
bs=1000 sw=10 sl=64	p99	1,073,753 us	968,353 us	1,093,309 us	+10.9%	-1.8%

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
0,10,10,64,20,501.99,200,128000,398,0.243,23777.48,32123.69,32123.69
1,100,10,64,20,2230.52,2000,1280000,897,0.547,109590.66,158101.79,158101.79
2,1000,10,64,20,18329.33,20000,12800000,1091,0.666,907890.43,1073753.39,1073753.39