remove segments joins from assign path

[bcb37]

No description provided.

[Copilot]

Pull request overview

This PR reduces database work on the /assign experiment read path by removing eager inclusion/exclusion segment joins from the “valid experiments” repository queries, and instead fetching only segment IDs lazily when the experiment_precomputed_segment row is missing and an on-the-fly segment resolution fallback is required.

Changes:

• Removed inclusion/exclusion segment joins from ExperimentRepository.getValidExperiments* and getValidExperimentsForContextAndDecisionPoint.
• Added ExperimentRepository.getSegmentIdsForExperiments() to fetch only inclusion/exclusion segmentIds for a scoped set of experiment IDs.
• Updated assignment-path logic and unit tests to use the new lazy segment-id lookup, including mock fixtures.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
packages/backend/src/api/services/ExperimentAssignmentService.ts	Switches segment resolution to a lazy, scoped lookup for experiments missing precomputed rows.
packages/backend/src/api/repositories/ExperimentRepository.ts	Removes eager segment joins from “valid experiments” queries and adds a lightweight segment-id query API.
packages/backend/test/unit/repositories/ExperimentRepository.test.ts	Updates expectations for reduced joins/queries and adds coverage for getSegmentIdsForExperiments.
packages/backend/test/unit/services/ExperimentAssignmentService.test.ts	Stubs the new repository method so existing assignment tests keep exercising fallback resolution.
packages/backend/test/unit/mockdata/raw.ts	Adds segmentId fields to inclusion/exclusion junction fixtures to match runtime expectations.

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.