Replace the status-bar model chip's modal with a Cursor-style dropdown:
- providers grouped by name in a stable order (no recency reshuffle on select)
- per-model hover-Edit submenu for reasoning effort + fast, gated by per-model
capabilities now surfaced in the model.options payload
- unified Fast toggle: flips the speed=fast param where supported, else swaps
to the model's `-fast` variant (base and variant collapse into one row)
- localStorage-backed "Edit Models" dialog to choose which models appear
Adds reusable dropdown primitives (DropdownMenuSearch, shared row/label
tokens, portaled + collision-aware submenus) and reads session state from
nanostores rather than prop-drilling, so editing options doesn't rebuild and
close the menu.
ea4fe15631