fix(worker): Speed up BundleAnalysisSaveMeasurements by bulk inserting timeseries data

[sentry]

The BundleAnalysisSaveMeasurements task was experiencing hard timeouts (720s) for bundle analysis reports with a large number of JavaScript assets. The root cause was identified as the _save_to_timeseries method being called and flushed individually for each JavaScript asset, leading to thousands of sequential database INSERT ... ON CONFLICT DO UPDATE operations.

This PR refactors the BundleAnalysisReportService.save_measurements method to collect all timeseries measurements (overall bundle size, individual JS asset sizes, and aggregated asset type sizes) into a single list. A new _save_to_timeseries_bulk method was introduced to perform a single bulk INSERT ... ON CONFLICT DO UPDATE operation for all collected measurements, followed by a single session.flush().

This change drastically reduces the number of database round-trips from O(N) (where N is the number of JS assets) to a constant O(1), eliminating the timeout issue and significantly improving the performance of bundle analysis measurement saving.

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Fixes WORKER-Z5E

[codecov-notifications]

Codecov Report

❌ Patch coverage is 90.00000% with 2 lines in your changes missing coverage. Please review.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
apps/worker/services/bundle_analysis/report.py	90.00%	2 Missing ⚠️

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[codecov]

Codecov Report

❌ Patch coverage is 90.00000% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 91.83%. Comparing base (d8942db) to head (f3fb9dd).
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
apps/worker/services/bundle_analysis/report.py	90.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1867      +/-   ##
==========================================
- Coverage   91.83%   91.83%   -0.01%     
==========================================
  Files        1332     1332              
  Lines       51830    51837       +7     
  Branches     1647     1647              
==========================================
+ Hits        47598    47603       +5     
- Misses       3911     3913       +2     
  Partials      321      321              

Flag	Coverage Δ
workerintegration	58.49% <5.00%> (-0.02%)	⬇️
workerunit	90.38% <90.00%> (-0.01%)	⬇️

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