feat(observability): deployment (OTel collector + Parca/eBPF)

[Ma77Ball]

What changes were proposed in this PR?

Provides the local deployment wiring that receives and stores telemetry. Default-off and isolated from the application services.

• Adds an OpenTelemetry Collector configuration and wires it into the single-node docker-compose stack.
• Adds the Parca server configuration and the Parca eBPF agent for continuous profiling.
• Updates the single-node up.sh and .env to start the observability backends.
• Infrastructure only; the application runs unchanged whether or not these services are started.

Any related issues, documentation, or discussions?

Closes: #5369
Part of #4070. Stacked on #5376.

How was this PR tested?

• Configuration-validation specs for the collector and Parca config.
• sbt scalafmtCheckAll passes; the build runs 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

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 51.63%. Comparing base (ce91924) to head (cba645e).

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #5377      +/-   ##
============================================
- Coverage     51.87%   51.63%   -0.24%     
+ Complexity     2467     2419      -48     
============================================
  Files          1067     1058       -9     
  Lines         41258    41069     -189     
  Branches       4437     4415      -22     
============================================
- Hits          21402    21206     -196     
- Misses        18595    18619      +24     
+ Partials       1261     1244      -17     

Flag	Coverage Δ		*Carryforward flag
access-control-service	42.22% <ø> (ø)
agent-service	33.76% <ø> (ø)		Carriedforward from 65aca57
amber	52.21% <ø> (-0.63%)	⬇️	Carriedforward from 65aca57
computing-unit-managing-service	1.65% <ø> (ø)
config-service	56.06% <ø> (ø)
file-service	38.32% <ø> (ø)
frontend	46.40% <ø> (+0.02%)	⬆️	Carriedforward from 65aca57
pyamber	90.67% <ø> (-0.02%)	⬇️	Carriedforward from 65aca57
python	90.83% <ø> (ø)		Carriedforward from 65aca57
workflow-compiling-service	58.69% <ø> (ø)

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

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