95 - AP: Visualize cross-account mapping

Account Plans in CRUSH often focus one Salesforce Account, but real pursuits span related legal entities and subsidiaries. This work adds cross-account mapping visualization on the Account Plan so strategists see how accounts connect (for example Parent Account hierarchies and other governed link types).

User story

As an account owner reviewing an Account Plan, I want to visualize related Salesforce accounts in context so I can align motions across the portfolio and spot coverage gaps without rebuilding org charts offline.