SymbolPicker: one well at rest, a 6x6 curated grid in a popover (leading
well = the level default, clearing the key), and an optional search over
the OS's full symbol inventory read from CoreGlyphs metadata. Geometry
font-derived off StyleEditorLayout's base, grid enlarged by a deliberate
1.3x. Wired inline with the rename field in the board info popover
through the StyleCommand funnel; the Title header retires. Curated set
and the search's standing vs 03's full-browser refusal await ratification.
