Keep View, Component, Runtime, reactive, Context, Resource, Behavior, Action, and Data in one core package; add the Grid Host lowering path; remove bundled UI and Playground copies; and document the independent package graph.
Deliver the unified View and Component model with retained Runtime, reactive scopes, Context, Behaviors, events, Actions, styles, Resources, Data, official UI Components, and Playground examples.\n\nVerification: make check and make load pass in the independent repository; sibling Ebox core tests pass 544/544.
