[rustfuture]

• Redraw: each frame is now built in a buffer, cleared and written at once, and text is clipped to the terminal. Rows that got shorter used to keep characters from earlier frames (e.g. 183424KBB), and in small terminals the process table and footer overlapped. Small terminals now get fewer graph/process rows instead of drawing off-screen.
• Graphs were upside down: values were mapped from the top grid row, so 8% CPU drew along the top edge. 0 is now the bottom row (one place, all graphs), with a unit test.
• --hide-processes leaves out the process table, for screen sharing and recordings; documented in the README.
• A recording of the dashboard (docs/demo/dashboard.tape, rendered with VHS, process table hidden) under the status note.

Checked: cargo fmt --check, clippy -D warnings, cargo test, cargo bench --no-run; the bugs were seen in recordings before the fix and are gone in the recording after it.