New general-purpose overlay component across all 4 layers (morfo/soma/sema/eidos)
plus a shared stacking layer and i18n catalog.
- Drag (2D free, anchored→free) + resize with device-pixel-snapped, GPU-composited
1:1 movement; elevation lifts on pointerdown for the pickup metaphor.
- Stages: minimize / maximize / restore (StageTrigger, computed maximized geometry
so restore needs no saved-rect bookkeeping).
- Composable header buttons: Controls + Action (custom) + Close + StageTrigger.
- Keyboard a11y (the industry gap): grab-mode move/resize on the focusable header
and a se-corner ResizeGrip (pointer + keyboard), with debounced live-region
announcements, bounds/min-max cues, aria-roledescription/keyshortcuts.
- Stacking registry (bring-to-front/topmost), Presence motion preset (scale-fade),
es/en langs catalog.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
