remove templates_classic counterparts of deleted cred/promote files

Mirrors the deletions in dojo/templates/dojo/ from the dev merge so the
classic Pro template tree doesn't carry orphaned references to the
removed Credential Manager and Stub Finding views.

Note: view_test.html, view_eng.html, view_finding.html, and base.html
in templates_classic still contain cred/stub_finding inline blocks
that reference removed URL names — separate follow-up.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: devGregA