feat: SMs for browser connect response

[ellisong]

Adds supportability metrics for failed responses on initializing the page_view_event aggregate.

Overview

Adds supportability metrics for failed responses from the browser connect service. We use this response to initialize our page view event feature as well as to know what aggregate features to start up for our remaining features. Any response that isn't a successful status code (>= http 400) will emit the following support metrics:

• Browser/Supportability/BCS/Error/StatusCode
  • The status code of the failed browser connect service response. Will always be a non-successful status code integer.
• Browser/Supportability/BCS/Error/Dropped/Bytes
  • Estimated amount of bytes dropped from our event backlog.
• Browser/Supportability/BCS/Error/Duration/Ms
  • The response time from sending the request to the browser connect service to receiving a response.

Related Issue(s)

JIRA: https://new-relic.atlassian.net/browse/NR-428192

Testing

Make sure WDIO tests pass.

Locally testing this outside WDIO is difficult since it requires getting an external service to intentionally fail its requests.

[github-actions]

Supportability Metric Usage Changes:

No matching changes found

Supportability Metrics .md File Changes:

supportability_metrics.md was changed? true

New supportability metrics require changes to supportability_metrics.md, as well as a new PR to Angler. Please ensure an Angler PR is created and linked to this PR.

[github-actions]

Asset Size Report

Merging this pull request will result in the following asset size changes:

Agent	Asset	Previous Size	New Size	Diff
lite	loader	25.96 kB / 9.8 kB (gzip)	25.96 kB / 9.8 kB (gzip)	0% / 0.01% (gzip)
lite	async-chunk	53.13 kB / 17.72 kB (gzip)	53.84 kB / 18.05 kB (gzip)	1.34% / 1.89% (gzip)
pro	loader	54.39 kB / 19.23 kB (gzip)	54.39 kB / 19.23 kB (gzip)	0% / -0.02% (gzip)
pro	async-chunk	91.78 kB / 28.8 kB (gzip)	92.49 kB / 29 kB (gzip)	0.77% / 0.7% (gzip)
spa	loader	63.19 kB / 21.91 kB (gzip)	63.19 kB / 21.91 kB (gzip)	0% / 0% (gzip)
spa	async-chunk	117.19 kB / 36.1 kB (gzip)	117.9 kB / 36.32 kB (gzip)	0.61% / 0.63% (gzip)

[codecov]

Codecov Report

❌ Patch coverage is 0% with 7 lines in your changes missing coverage. Please review.
✅ Project coverage is 88.52%. Comparing base (b502684) to head (fe8fc5f).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/features/page_view_event/aggregate/index.js	0.00%	6 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1611      +/-   ##
==========================================
- Coverage   88.60%   88.52%   -0.08%     
==========================================
  Files         206      206              
  Lines        7746     7753       +7     
  Branches     1586     1587       +1     
==========================================
  Hits         6863     6863              
- Misses        772      778       +6     
- Partials      111      112       +1     

Flag	Coverage Δ
unit-tests	81.77% <0.00%> (-0.11%)	⬇️

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[github-actions]

Last ran on October 30, 2025 17:22:09 CDT
Checking merge of (7366f50) into main (09ff9b3)

[ellisong]

angler PR: https://source.datanerd.us/agents/angler/pull/760