chore(frontend): remove dead select-recommendations-modal markup #1652

Summary

#select-recommendations-modal markup has no opener anywhere, so it is dead.

Current behaviour

frontend/src/index.html (~line 1119) defines the modal and frontend/src/app.ts (~line 335-345) wires its close/confirm buttons, but nothing opens it. The confirm handler body is empty.

Steps to reproduce

Search frontend/src (excluding tests) for any call that opens select-recommendations-modal; there is none.

Expected behaviour

No unreachable modal markup or handlers.

Proposed fix

Remove the modal from frontend/src/index.html, its handlers in frontend/src/app.ts and the check in frontend/src/tests/html.test.ts (~line 341).

References

Discovered while reviewing #1598.

Severity

low