PaneManager

Context

Pane layout state and sub-indicator state describe one user-visible object: a sub pane exists together with the indicator it renders. Previously, layout mutations could update PaneSpec[] separately from indicator instances, allowing an orphaned pane or an orphaned indicator projection.

Decision

PaneManager is the only pane domain write boundary. Its actions are create, update, remove, move, replaceContent, updateContent, and clear.

create, remove, and clear use one batch() to publish the pane layout and indicator instance snapshots together. ChartStateKernel.actions does not expose pane mutations. ChartPaneLayout now receives snapshots through projectState() and retains only renderer/layout working data needed to paint the current frame.

The complete-layout importer is intentionally separate from ordinary Actions. It is used only when a controlled chart configuration is loaded and removes user-owned sub-indicator instances for panes omitted by that imported snapshot. It is not an Agent or UI mutation API.

Consequences

Framework controllers expose the same pane Actions and no longer expose createSubPane, replaceSubPaneIndicator, updatePaneLayout, or pixel-delta resizeSubPane APIs. UI drag behavior remains an interaction concern and must translate its result to PaneManager.actions.update.

Agent tool registration is the next integration step: it must wrap a documented subset of PaneManager.actions, never duplicate their domain logic or mutate PaneState/IndicatorState directly.

Agent Tools

The Agent exposes panes_list as a read-only projection. Mutation tools map one-to-one to the public PaneManager actions: pane_create, pane_update, pane_remove, pane_move, pane_replace_content, pane_update_content, and panes_clear.

Agent inputs never include instanceId or ordinal; PaneManager creates those identities. The indicator orchestration path can provide a previously allocated identity through its internal createFromIndicator() integration method so addIndicator() retains its returned instance contract.