[fix][evaluation] ExptInsightAnalysisService add start/end time

[xueyizheng]

What type of PR is this?

ExptInsightAnalysisService add start/end time for InsightReport analysis

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[CozeLoop]

Code Review Summary: Added validation and API design feedback for start/end time propagation in insight analysis, flagged a must-fix for interface change impacting mocks/tests, and marked safe changes. Please see inline comments for actionable guidance.

[codecov]

Codecov Report

❌ Patch coverage is 82.75862% with 5 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...evaluation/domain/service/insight_analysis_impl.go	80.95%	3 Missing and 1 partial ⚠️
...evaluation/infra/mq/rocket/consumer/expt_export.go	0.00%	1 Missing ⚠️

@@           Coverage Diff           @@
##             main     #284   +/-   ##
=======================================
  Coverage        ?   68.42%           
=======================================
  Files           ?      569           
  Lines           ?    51661           
  Branches        ?        0           
=======================================
  Hits            ?    35347           
  Misses          ?    13569           
  Partials        ?     2745           

Flag	Coverage Δ
unittests	68.42% <82.75%> (?)

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Files with missing lines	Coverage Δ
...d/modules/evaluation/application/experiment_app.go	77.67% <100.00%> (ø)
backend/modules/evaluation/domain/entity/event.go	0.00% <ø> (ø)
...ackend/modules/evaluation/infra/rpc/agent/agent.go	66.66% <100.00%> (ø)
...evaluation/infra/mq/rocket/consumer/expt_export.go	0.00% <0.00%> (ø)
...evaluation/domain/service/insight_analysis_impl.go	96.17% <80.95%> (ø)

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