fix(repository): dedupe/filter source ids before querying in hasManyThrough inclusion resolver

[karthikchundi-commits]

hasManyThrough's inclusion resolver passes its raw, unfiltered sourceIds array by reference straight into findByForeignKeys(), which wraps it in an {inq: [...]} where clause and hands that same array to the connector without cloning it first. A connector/query layer that sanitizes an inq array in place (e.g. stripping falsy values before running the query, as the in-memory connector does) then mutates that exact array out from under the caller — shrinking the very sourceIds array the resolver still needs below, unmodified, to correctly zip through-results back onto each original entity via flattenTargetsOfOneToManyRelation(). That silently misaligns or truncates the returned array whenever any source entity's key was undefined (e.g. excluded by a fields filter) or duplicated another entity's.

hasMany and hasOne inclusion resolvers already had this exact bug fixed (deduplicate(sourceIds).filter(e => e) before querying, same aliasing hazard, same root cause). hasManyThrough had no dedup/filter attempt at all — not even a partial one, unlike hasMany/hasOne before their own fix.

Found via a source-reading sweep of the other relation-inclusion resolvers (belongsTo, referencesMany) after noticing the pattern already fixed for hasMany/hasOne — belongsTo and referencesMany were independently reconfirmed clean (both already pass a genuinely fresh, deduplicated array, never the original reference).

Checklist

• DCO (Developer Certificate of Origin) signed in all commits
• npm test passes on your machine
• New tests added or existing tests modified to cover all changes — added a regression test to has-many-through-inclusion-resolver.acceptance.ts mirroring the existing hasMany/hasOne regression tests: a duplicate source entity plus one with an undefined key, confirming the result stays length-3 and aligned with the input. Verified the test actually catches the bug by temporarily reverting the source fix and re-running — reproduces the exact truncation (length 2 instead of 3) this fix addresses.
• Code conforms with the style guide — eslint and prettier both clean on the two changed files

Testing

cd packages/repository && npm run build
cd packages/repository-tests && npm run build
npx mocha "dist/__tests__/**/*.js"

126 passing, 8 pending (pre-existing, unrelated to this change), no failures.