Rename refresh-bar -> refresh-shell, restart-quickshell -> restart-shell

The bin names should reflect the thing they manage. `refresh bar` is
misleading because the command resets the entire shell.json (which holds
plugins beyond just the bar), and `restart quickshell` names the runtime
rather than the product. Both now end in `-shell` to match the rest of
omarchy-shell.

Updates every caller in autostart, the menu, voxtype helpers, and the
shell README. No behavior changes.

bin/omarchy-restart-shell

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+# omarchy:summary=Restart the Omarchy shell
+# omarchy:examples=omarchy restart shell
+
+OMARCHY_PATH=${OMARCHY_PATH:-$HOME/.local/share/omarchy}
+CONFIG_DIR="$OMARCHY_PATH/default/quickshell/omarchy-shell"
+
+quickshell kill -p "$CONFIG_DIR" >/dev/null 2>&1 || true
+setsid uwsm-app -- env OMARCHY_PATH="$OMARCHY_PATH" quickshell -p "$CONFIG_DIR" >/dev/null 2>&1 &