feat(observability): profiles end-to-end (gateway + UI panel)

[Ma77Ball]

What changes were proposed in this PR?

Continuous-profiling retrieval through the gateway plus a flame-graph UI panel.
Backend:

• ParcaClient: gRPC-Web client to the Parca server, with a profiles query builder and parseProfiles.
• ProfilesResource exposing scoped profile queries (optional workflow and execution id), registered in TexeraWebApplication.
  Frontend:
• Profiles panel with a flame-chart component, scoped by workflow and execution id, with explicit empty states for "no samples yet" and for environments where profiling is disabled.

Any related issues, documentation, or discussions?

Closes: #5374
Part of #4070. Stacked on #5381.

How was this PR tested?

• Backend specs for ParcaClient, the profiles query builder, and the parser; sbt scalafmtCheckAll passes.
• Frontend profiles-panel and flame-chart specs; prettier-eslint and eslint pass.
• Compile and the full test suites run in this PR's CI.

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

Co-authored with Claude Opus 4.8 in compliance with ASF

[codecov-commenter]

Codecov Report

❌ Patch coverage is 60.35645% with 823 lines in your changes missing coverage. Please review.
✅ Project coverage is 50.69%. Comparing base (dfa0434) to head (917e46d).

Files with missing lines	Patch %	Lines
...observability/gateway/ObservabilityResources.scala	0.00%	264 Missing ⚠️
...texera/web/observability/gateway/ParcaClient.scala	33.71%	109 Missing and 7 partials ⚠️
...observability/logs-panel/logs-panel.component.html	56.92%	55 Missing and 1 partial ⚠️
...ala/org/apache/texera/observability/OtelInit.scala	63.30%	43 Missing and 8 partials ⚠️
...apache/texera/web/observability/gateway/dtos.scala	76.96%	37 Missing and 7 partials ⚠️
...texera/web/observability/gateway/AuditLogger.scala	0.00%	41 Missing ⚠️
...xera/web/observability/gateway/ScopeResolver.scala	19.44%	27 Missing and 2 partials ⚠️
...ra/web/observability/gateway/ResponseParsers.scala	81.06%	2 Missing and 23 partials ⚠️
...era/web/observability/gateway/GatewayContext.scala	0.00%	19 Missing ⚠️
...rvability/traces-panel/traces-panel.component.html	44.11%	19 Missing ⚠️
... and 20 more

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #5382      +/-   ##
============================================
- Coverage     52.91%   50.69%   -2.23%     
- Complexity     2626     2670      +44     
============================================
  Files          1090      985     -105     
  Lines         42188    36793    -5395     
  Branches       4531     4950     +419     
============================================
- Hits          22324    18651    -3673     
+ Misses        18555    16726    -1829     
- Partials       1309     1416     +107     

Flag	Coverage Δ
access-control-service	70.91% <ø> (ø)
agent-service	?
amber	52.92% <51.65%> (-0.09%)	⬇️
computing-unit-managing-service	1.65% <ø> (ø)
config-service	56.71% <ø> (ø)
file-service	57.06% <ø> (ø)
frontend	49.01% <79.32%> (+1.08%)	⬆️
pyamber	?
python	?
workflow-compiling-service	58.69% <ø> (ø)

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[github-actions]

⚠️ Benchmark changes need a look

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

Compared against main dfa0434 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	397	0.242	24,868/34,503/34,503 us	🟢 -53.3% / ⚪ within ±5%
🔴	bs=100 sw=10 sl=64	950	0.58	104,592/134,607/134,607 us	🔴 +21.4% / 🟢 -6.8%
⚪	bs=1000 sw=10 sl=64	1,125	0.687	887,141/940,604/940,604 us	⚪ within ±5% / 🟢 -8.8%

Baseline details

Latest main dfa0434 from same runner

config	metric	PR	latest main	7d avg	Δ latest	Δ 7d
bs=10 sw=10 sl=64	throughput	397 tuples/sec	363 tuples/sec	410.82 tuples/sec	+9.4%	-3.4%
bs=10 sw=10 sl=64	MB/s	0.242 MB/s	0.222 MB/s	0.251 MB/s	+9.0%	-3.5%
bs=10 sw=10 sl=64	p50	24,868 us	24,354 us	23,785 us	+2.1%	+4.6%
bs=10 sw=10 sl=64	p95	34,503 us	73,948 us	34,980 us	-53.3%	-1.4%
bs=10 sw=10 sl=64	p99	34,503 us	73,948 us	34,980 us	-53.3%	-1.4%
bs=100 sw=10 sl=64	throughput	950 tuples/sec	993 tuples/sec	891.94 tuples/sec	-4.3%	+6.5%
bs=100 sw=10 sl=64	MB/s	0.58 MB/s	0.606 MB/s	0.544 MB/s	-4.3%	+6.5%
bs=100 sw=10 sl=64	p50	104,592 us	100,961 us	112,277 us	+3.6%	-6.8%
bs=100 sw=10 sl=64	p95	134,607 us	110,878 us	139,802 us	+21.4%	-3.7%
bs=100 sw=10 sl=64	p99	134,607 us	110,878 us	139,802 us	+21.4%	-3.7%
bs=1000 sw=10 sl=64	throughput	1,125 tuples/sec	1,131 tuples/sec	1,041 tuples/sec	-0.5%	+8.1%
bs=1000 sw=10 sl=64	MB/s	0.687 MB/s	0.69 MB/s	0.635 MB/s	-0.4%	+8.1%
bs=1000 sw=10 sl=64	p50	887,141 us	896,307 us	972,714 us	-1.0%	-8.8%
bs=1000 sw=10 sl=64	p95	940,604 us	939,985 us	1,023,057 us	+0.1%	-8.1%
bs=1000 sw=10 sl=64	p99	940,604 us	939,985 us	1,023,057 us	+0.1%	-8.1%

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
0,10,10,64,20,503.91,200,128000,397,0.242,24867.98,34503.38,34503.38
1,100,10,64,20,2105.09,2000,1280000,950,0.580,104591.60,134607.09,134607.09
2,1000,10,64,20,17777.18,20000,12800000,1125,0.687,887140.75,940604.30,940604.30