fix: improve member deduplication by parsing GitHub noreply emails (CM-958)

[skwowet]

Summary

• Add parseGitHubNoreplyEmail utility to extract GitHub usernames from ID+USERNAME@users.noreply.github.com and USERNAME@users.noreply.github.com email formats
• Look up existing members by derived GitHub username during activity ingestion, preventing duplicate profile creation
• Add noreply email matching to merge suggestions OpenSearch queries and similarity scoring for better deduplication of existing profiles
• Fix hasClashingMemberIdentities to only compare USERNAME identities, preventing false clashes when EMAIL identities exist on the same platform

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Note

Medium Risk
Touches member-resolution and merge-suggestion logic, which can change how profiles are deduplicated and merged; mistakes could cause incorrect member attribution or missed merges, but the change is scoped to GitHub noreply email parsing/matching.

Overview
Improves member deduplication by adding parseGitHubNoreplyEmail and using it to treat GitHub @users.noreply.github.com emails as a source of the underlying GitHub username.

During activity ingestion (activity.service.ts), verified noreply emails are parsed and used to look up existing members by verified GitHub usernames before creating new members (applies to both member and objectMember).

In merge suggestions, OpenSearch queries now include noreply-email-derived username matches, similarity scoring treats noreply-email↔username matches as high confidence, and hasClashingMemberIdentities is narrowed to compare only USERNAME identities to avoid false clashes.

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[Copilot]

Pull request overview

This PR improves member deduplication by extracting GitHub usernames from @users.noreply.github.com emails and using that derived username for both ingestion-time member resolution and merge-suggestion matching.

Changes:

• Added parseGitHubNoreplyEmail utility to derive GitHub usernames from noreply email formats.
• Updated merge-suggestions similarity scoring and OpenSearch queries to consider noreply-email-to-username matches.
• Updated activity ingestion to look up existing members by derived GitHub username and to attach an unverified GitHub username identity to new members when a noreply email is present.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
services/libs/common/src/email.ts	Adds GitHub noreply email parsing helper.
services/apps/merge_suggestions_worker/src/memberSimilarityCalculator.ts	Incorporates noreply-email-derived username matching into similarity scoring and adjusts clashing identity logic.
services/apps/merge_suggestions_worker/src/activities/memberMergeSuggestions.ts	Adds OpenSearch clause to match derived GitHub usernames from noreply emails.
services/apps/data_sink_worker/src/service/activity.service.ts	Resolves members during ingestion via derived GitHub usernames and appends unverified GitHub username identities for new members.

Comments suppressed due to low confidence (1)

services/apps/merge_suggestions_worker/src/memberSimilarityCalculator.ts:205

• hasClashingMemberIdentities compares usernames using a case-sensitive inequality (i.keyword_value !== identity.value). Since identity matching elsewhere (e.g., SQL lookups) is case-insensitive, this can incorrectly treat values that differ only by casing as a clash and force a low similarity score. Consider normalizing both sides (e.g., lowercase) before comparing, and guard against missing values.

          similarMember.nested_identities.some(
            (i) =>
              i.keyword_type === MemberIdentityType.USERNAME &&
              i.string_platform === identity.platform &&
              i.keyword_value !== identity.value,
          )

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[CLAassistant]

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[cursor]

Cursor Bugbot has reviewed your changes and found 2 potential issues.

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