Follow-up to #749.

Objective

Document sensitivity checks for RD/RKink workflows.

Scope

• Add/update RD/RKink docs with bandwidth/manipulation diagnostics coverage
• Include interpretation caveats and practical thresholds guidance

Acceptance criteria

• RD/RKink docs include a concise sensitivity section
• Terminology aligns with central guide
• Links back to matrix and workflow docs

Parent issue: #785