[aff] schema-validate .reps./.func. LIMU sub-object examples (tasks 0.4a) #245

OpenSpec task 0.4a — unchecked in `add-aff-full-coverage`

The conformance harness validates root AFF metadata + `.docu.`
companions against official schemas. `.reps.` / `.func.` LIMU
sub-object examples are counted but not schema-validated — their
schemas nest under the parent type dir (`file-formats/fugr/func-v1.json`,
`fugr/reps-v1.json`).

Fix direction: route LIMU example files in
`tests/aff/schema-conformance.test.ts` to their nested schemas —
`affSchema({ type: 'func' })` / `affSchema({ type: 'reps' })` already
resolve nested dirs (added in PR #232); the harness just needs to map
`*.{func,reps}.{json,abap}` companions to those types.

Then check off `openspec/changes/add-aff-full-coverage/tasks.md` → 0.4a.