Rename shared VariableBar activation port to caller-neutral names

[BorisTyshkevich]

Problem

VariableBarApp is shared by Dashboard and detached Data, but its activation port is named after Workbench persistence:

• state.filterActive
• params.saveFilterActive

That naming leaks one caller's storage model into a shared UI contract. Dashboard uses the same members for an in-memory draft map with no persistence, while detached Data uses the persisted Workbench map.

Current behaviour is correct, but the shared port is misleading and makes adapters easier to implement incorrectly.

Change

Rename only the shared VariableBarApp members to caller-neutral names, for example:

• state.activeByName
• params.saveActive

Keep all persisted Workbench names and storage unchanged:

• AppState.filterActive
• WorkbenchParameterSession.saveFilterActive
• effectiveFilterActive
• asb:filterActive

Both callers should construct explicit adapters. The activation map must be aliased, not copied, because the variable bar mutates it in place.

Acceptance criteria

• VariableBarApp contains no filter-specific activation member names.
• Dashboard aliases its local draft activation map.
• Detached Data aliases app.state.filterActive and routes saveActive to app.params.saveFilterActive().
• No persisted state or storage-key migration is introduced.
• A detached Data integration test proves that editing a variable updates the real AppState.filterActive object and calls saveFilterActive().
• Existing variable-bar, Dashboard, architecture, and end-to-end tests remain green.