TUI shell

Session cards stop collapsing to one line, the TUI sidebar gains project grouping and a themeable palette, focus becomes visible, and bare maestro opens the TUI.

The card contract is docs/SIDEBAR.md; the TUI colour rules it fixes live in its "Colour per activity state" section, and the line-2 rules in "Line 2 — meta line (adaptive)". Goal: a sidebar whose rows do not change height under the eye, whose groups match the web's, and whose colours are legible and the operator's to choose.

No due date
100% Completed