Revises breadcrumbs and subsites to rely on depth properly

Editor assessment

The subject says breadcrumbs and subsites now 'rely on depth properly', but neither the prior incorrect reliance nor the corrected depth semantics are stated, so the substantive lesson stays in the diff. The feat type is arguable for what sounds like a correction, though the rubric tolerates straddling choices. No scope or body explains the navigation-model change, which is exactly where context would help readers of the history. Style is clean otherwise. Understandable at the surface, but the hedging adverb and missing rationale keep it at acceptable.