[devin-ai-integration]

What and why

The migrator, runtime, solver, analysis framework, document planner, API JSON writer, semantics package and the tools module each carried their own ==-loop membership or index helper (contains, containsElement, containsSymbol, containsFit, containsInstance, containsFeatureValue, indexOfSymbol, joins, containsColumn, indexOfAPIJSONProperty, containsInt, containsString, Query.declares, containsWord, appendUnique, lastName) that duplicate slices.Contains, slices.ContainsFunc and slices.Index from the standard library, which the module already uses widely. This PR deletes the helpers and calls slices.* directly at every call site; tools/census/metaclassmap/analyze.go spells the last segment of a qualified name through the existing symbols.LastSegment instead of its own lastName. indicesWithFit in internal/semantic/semantics/invocation.go stays because it still has other callers.

Pure refactor, no behaviour change: every replacement keeps the same equality, first-match, empty-slice and -1-for-absent semantics. Test-only callers (members_test.go, robustness_extent_model_determined_test.go) now call slices.* directly; no test was removed or weakened.

Editing internal/translate/export/api_json_out.go moves the API JSON writer's source digest, so docs/project/api-json-differential-baseline.json is re-recorded with go run -C tools ./cmd/pilot-apijson-diff -update: only provenance.tools[api-json-writer].sourceDigest and recorded changed; every measured figure is identical.

How it was verified

go build ./...                      ok
go vet ./...                        ok
gofmt -l .                          (no output)
go test -count=1 -timeout 45m ./... ok (all packages)
cd tools && go build ./... && go vet ./... && gofmt -l . && go test -count=1 ./...   ok

The tools suite was run after re-recording the baseline (the tools/referee/apijson provenance test fails deliberately when internal/translate/export changes without a re-record).

Checklist

• make test and make lint pass locally
• Tests added or updated for the change (existing tests cover every call site; test-only callers repointed)
• Documentation extended where it already covers the surface (see CONTRIBUTING.md)
• Changelog entry added as changes/unreleased/slices-contains-helpers.changed.md, not as an edit to CHANGELOG.md
• baselines regenerated and make docs-counts run if a gate count moved (only the API JSON baseline's provenance moved; no count changed)
• No internal work-item labels in the body, docs, or changelog

Link to Devin session: https://nasa-jpl-demo.devinenterprise.com/sessions/d47554ed93494ba4a374cbe22108a0cb
Open in Devin Desktop: https://nasa-jpl-demo.devinenterprise.com/desktop/session/d47554ed93494ba4a374cbe22108a0cb?variant=devin
Requested by: @HuiJun

[devin-ai-integration]

I'll fix CI failures and address comments from users with write access. I'll skip comments containing "(aside)".

• Disable automatic comment, CI, and merge conflict monitoring

[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no bugs or issues to report.