Name the project Keystone, and move its paths and namespaces

The repository had no name of its own, only the framework's. It is now
Keystone, in the README, AGENTS.md, the settings window, notes commit
messages, calctl's PRODID and the user page's User-Agent.

Its files move off quickshell's name too:

  ~/.config/quickshell/greetings             -> ~/.config/keystone/
  ~/.config/quickshell/obs-scene-icons.json  -> ~/.config/keystone/
  $XDG_STATE_HOME/quickshell/desktop.json    -> $XDG_STATE_HOME/keystone/

~/.config/quickshell is Quickshell's own default config directory (a
bare qs loads its shell.qml), so sharing it was a collision rather than
a home. There is no fallback to the old paths: the files are moved once.

The layer namespaces become keystone-*, and the Hyprland blur rules in
hypr-theme are renamed to match in the same change. A running shell
keeps its old namespaces until restarted.

Left alone: the retired standalone mail and vm shells' namespaces,
which their READMEs keep as history; Quickshell's own app id, binary
and process name; and the repository directory.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 5 insertions, 4 deletions

diff --git a/README.md b/README.md
index 1141645..d06723c 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,9 @@
-# quickshell
+# Keystone
 
-Quickshell components for a Hyprland desktop, each one self-contained in its
-own directory. `desktop/` is the integrated one: a single process hosting the
-drawer and the island, and later a control panel, which its own README covers.
+Keystone is a set of Quickshell components for a Hyprland desktop, each one
+self-contained in its own directory. `desktop/` is the integrated one: a single
+process hosting the drawer and the island, and later a control panel, which its
+own README covers.
 The rest are separate shells: any of them can run alone, and running one does
 not require the others.