The top of the left column shows the project name and the current canvas — the name is also a dropdown: open it to switch projects, create a new one, or delete the current one — every row carries the project's cover thumbnail, since a column of "Untitled" projects is impossible to tell apart by name alone. The strip below it has two tabs, Canvas and Asset. The Asset tab splits into two further tabs, Personal and Agent: Personal holds the material kept in your asset library (it spans canvases and follows your account) — click a row and it drops onto the canvas; Agent holds the nodes the Agent built on this canvas. Under that is the node list, and the small buttons to its right handle sorting, filtering by type and search. The button at the right end of the tab row opens Assets, where folders, uploads and batch management live; the row in that dialog's title switches between Assets and Subject library (see 10.7).
Both columns start collapsed, leaving the whole screen to the canvas; their open / collapsed state is remembered per project, so collapsing one project does not affect another. Collapse the left column from the button at its bottom-left — a pill then floats at the top-left that keeps showing the project and the canvas, and you bring the column back with Assets, which joins the group of controls at the bottom-left. Collapse Agent from the rightmost button in its header — an AI Agent button then stays at the top-right to call it back. Drag either column's edge to resize it — the width you set survives a refresh.
On a phone the canvas takes the whole screen and both columns become drawers: pull the left one out with Assets at the bottom-left, and Agent with the chat icon on the bottom toolbar.