Removing #rightrail left a dead 360px grid column that narrowed #main.
Shell grid is now sidebar+main; the topbar ◆ (was Toggle-companion-rail)
now dispatches dross-toggle to open/close the floating bubble. Remaining
.rail-* CSS + chrome.js toggleRail are dead no-ops (minor cleanup later).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Adds dross_bubble.js — a fixed FAB orb that opens a draggable,
anchored panel wired to wireAgentChat. Mic button rendered but
disabled (Phase 2). Swaps renderRightrail call in app.js; removes
dead <aside id="rightrail"> from index.html. rightrail.js kept in
place (unused).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>