fix(amber): classify wrapped sync timeouts

[anthonychengit]

What changes were proposed in this PR?

RxJava's blockingGet can wrap a checked TimeoutException. The previous catch matched only a direct timeout, so a wrapped timeout fell through to the generic error handler and returned Error instead of Killed.

Before: timeout -> wrapper exception -> generic handler -> Error
After:  timeout -> cause-chain check -> timeout handler -> Killed

This change classifies an exception as a timeout when any safe, finite link in its cause chain is a TimeoutException. Tests cover direct and nested timeouts as positive cases, plus unrelated exceptions and null as negative cases.

Any related issues, documentation, discussions?

Closes #6198

How was this PR tested?

sbt "WorkflowExecutionService / Test / testOnly org.apache.texera.web.resource.SyncExecutionResourceSpec -- -z isCausedByTimeout"
sbt scalafmtCheckAll
sbt "scalafixAll --check"

The focused timeout-classification tests passed. Scala formatting and Scalafix checks also passed.

I also ran the complete SyncExecutionResourceSpec. The new timeout cases passed; 8 pre-existing storage-result cases could not complete because the local Iceberg REST catalog expected at localhost:8181 was not running. Those cases are outside this change and will be exercised by the repository CI environment.

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

Generated-by: OpenAI Codex (GPT-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:

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

[github-actions]

⚠️ Benchmark changes need a look

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

Compared against main 12169c2 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	402	0.245	24,069/31,788/31,788 us	🟢 -9.2% / 🔴 +94.4%
⚪	bs=100 sw=10 sl=64	804	0.491	121,813/150,022/150,022 us	⚪ within ±5% / 🔴 +39.4%
⚪	bs=1000 sw=10 sl=64	905	0.552	1,102,980/1,146,747/1,146,747 us	⚪ within ±5% / 🔴 -12.2%

Baseline details

Latest main 12169c2 from same runner

config	metric	PR	latest main	7d avg	Δ latest	Δ 7d
bs=10 sw=10 sl=64	throughput	402 tuples/sec	429 tuples/sec	774.89 tuples/sec	-6.3%	-48.1%
bs=10 sw=10 sl=64	MB/s	0.245 MB/s	0.262 MB/s	0.473 MB/s	-6.5%	-48.2%
bs=10 sw=10 sl=64	p50	24,069 us	22,740 us	12,738 us	+5.8%	+88.9%
bs=10 sw=10 sl=64	p95	31,788 us	35,012 us	16,348 us	-9.2%	+94.4%
bs=10 sw=10 sl=64	p99	31,788 us	35,012 us	18,848 us	-9.2%	+68.7%
bs=100 sw=10 sl=64	throughput	804 tuples/sec	814 tuples/sec	1,005 tuples/sec	-1.2%	-20.0%
bs=100 sw=10 sl=64	MB/s	0.491 MB/s	0.497 MB/s	0.613 MB/s	-1.2%	-19.9%
bs=100 sw=10 sl=64	p50	121,813 us	121,776 us	100,970 us	+0.0%	+20.6%
bs=100 sw=10 sl=64	p95	150,022 us	153,249 us	107,605 us	-2.1%	+39.4%
bs=100 sw=10 sl=64	p99	150,022 us	153,249 us	116,429 us	-2.1%	+28.9%
bs=1000 sw=10 sl=64	throughput	905 tuples/sec	919 tuples/sec	1,030 tuples/sec	-1.5%	-12.2%
bs=1000 sw=10 sl=64	MB/s	0.552 MB/s	0.561 MB/s	0.629 MB/s	-1.6%	-12.2%
bs=1000 sw=10 sl=64	p50	1,102,980 us	1,082,721 us	991,433 us	+1.9%	+11.3%
bs=1000 sw=10 sl=64	p95	1,146,747 us	1,152,160 us	1,036,668 us	-0.5%	+10.6%
bs=1000 sw=10 sl=64	p99	1,146,747 us	1,152,160 us	1,070,470 us	-0.5%	+7.1%

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
0,10,10,64,20,497.44,200,128000,402,0.245,24068.70,31788.23,31788.23
1,100,10,64,20,2486.97,2000,1280000,804,0.491,121813.37,150021.83,150021.83
2,1000,10,64,20,22101.37,20000,12800000,905,0.552,1102979.75,1146747.43,1146747.43

[codecov-commenter]

Codecov Report

❌ Patch coverage is 71.42857% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 89.65%. Comparing base (12169c2) to head (0c4367e).
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
...he/texera/web/resource/SyncExecutionResource.scala	71.42%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #7640      +/-   ##
============================================
- Coverage     89.65%   89.65%   -0.01%     
- Complexity     4397     4401       +4     
============================================
  Files          1177     1177              
  Lines         46996    47004       +8     
  Branches       5268     5272       +4     
============================================
+ Hits          42136    42140       +4     
- Misses         3094     3097       +3     
- Partials       1766     1767       +1     

Flag	Coverage Δ		*Carryforward flag
access-control-service	70.00% <ø> (ø)		Carriedforward from 12169c2
agent-service	98.62% <ø> (ø)		Carriedforward from 12169c2
amber	86.33% <71.42%> (-0.02%)	⬇️
computing-unit-managing-service	72.46% <ø> (ø)		Carriedforward from 12169c2
config-service	77.31% <ø> (ø)		Carriedforward from 12169c2
file-service	68.90% <ø> (ø)		Carriedforward from 12169c2
frontend	90.67% <ø> (ø)		Carriedforward from 12169c2
notebook-migration-service	78.89% <ø> (ø)		Carriedforward from 12169c2
pyamber	97.57% <ø> (ø)		Carriedforward from 12169c2
workflow-compiling-service	57.89% <ø> (ø)		Carriedforward from 12169c2

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

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