Teach the launcher what an operating system knows

The OS-parity batch from the vicinae plan, tasks 1 through 7. The audit
came back better than the plan guessed: the calculator already links
libqalculate, the built-in file index answers in under 100ms across all
of home, quicklinks and snippets ship as built-in stores -- so zero new
packages, and `vicinae dmenu` replaces the planned compiled extension
outright. What was missing gets built: a power menu (lock, suspend, log
out through uwsm, restart, power off), reminders as transient systemd
timers with a pick-to-cancel list, a color picker over hyprpicker, and
dmenu pick-lists for window switching, force quit, kill process, SSH
hosts, and recent files -- all through one panama-pick helper. The
launcher commands contract exercises the reminder parsing and every
pick-list against stubs, including killing its own sacrificial sleep.

config/local/share/vicinae/scripts/log-out

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+# @vicinae.schemaVersion 1
+# @vicinae.title Log Out
+# @vicinae.mode silent
+# @vicinae.icon ../../icons/hicolor/scalable/apps/panama-settings.svg
+# @vicinae.description End the session and return to the login screen.
+# @vicinae.keywords ["logout", "log out", "sign out", "exit", "session"]
+
+# uwsm owns the session (see the hypr README), so it gets to end it: units stop
+# in order instead of being orphaned by a bare compositor exit. The dispatch is
+# the fallback for the plain non-uwsm session.
+if command -v uwsm >/dev/null 2>&1; then
+  exec uwsm stop
+fi
+exec hyprctl dispatch exit