refactor(quickshell): drop the Persona names from the primitives

P5Panel, P5Button, P5Slider and P5Tooltip become Panel, ActionButton,
LevelSlider and Tooltip. ActionButton and LevelSlider avoid clashing
with QtQuick.Controls, which the ask panel imports.

quickshell/README.md

@@ -74,7 +74,7 @@ backdrop/        the wallpaper, drawn by the shell
 assets/          halftone and stripe tiles, generated with ImageMagick
 ```
 
-`P5Panel` is the base surface everything sits on. It does not auto-size —
+`Panel` is the base surface everything sits on. It does not auto-size —
 callers set implicit sizes from their own layout (`row.implicitWidth +
 contentPad * 2`), which keeps the shape maths out of binding loops.
 
@@ -441,7 +441,7 @@ zones itself, so every piece is placed from the screen edge.
 
 **Soft, everywhere else.** The porthole is the shape the desktop is built
 around, and every smaller surface is a gentler echo of it. `Theme.skew` and
-`Theme.cut` are `0`; `P5Panel` and `Skew` draw `Geom.roundedRect` with
+`Theme.cut` are `0`; `Panel` and `Skew` draw `Geom.roundedRect` with
 `Theme.radiusS` (pills, chips, meter tracks), `radiusM` (rows, buttons) or
 `radiusL`. `radiusL` is `frameRadius - padS`: anything inset by `padS` inside
 one of the frame's curves — a hovered notification in the drawer's corner —