Fix boot-critical, session, and UX bugs found in round-3 UX audit

Snapshots panel was non-functional (wrong snapper flag); breadgreet picked
the wrong session .desktop and skipped bos-session's PATH fixup; Calamares
aborted offline installs over an unnecessary packages module; snapshot
rollback silently no-op'd on BOS's pinned-subvolume layout (now points at
grub-btrfs instead); breadcrumbs was configurable but had no daemon to run
it. Also: SUPER+I double-bind, breadpaper/packages panels blocking the GTK
main thread, dead polkit rule, and a sweep of smaller drift (default
sidebar view, stale wording, missing .desktop launchers, wallpaper daemon
not recording its own default).

iso/airootfs/etc/skel/.local/share/applications/breadclip.desktop

@@ -0,0 +1,9 @@
+[Desktop Entry]
+Name=breadclip
+Comment=Clipboard history
+Exec=breadclip
+Icon=edit-paste
+Terminal=false
+Type=Application
+Categories=Utility;
+StartupWMClass=breadclip

iso/airootfs/etc/skel/.local/share/applications/breadman.desktop

@@ -0,0 +1,9 @@
+[Desktop Entry]
+Name=breadman
+Comment=Notes and reminders manager
+Exec=breadman
+Icon=accessories-text-editor
+Terminal=false
+Type=Application
+Categories=Utility;Office;
+StartupWMClass=breadman

iso/airootfs/etc/skel/.local/share/applications/breadmon.desktop

@@ -0,0 +1,9 @@
+[Desktop Entry]
+Name=breadmon
+Comment=Monitor layout manager (TUI)
+Exec=breadmon
+Icon=video-display
+Terminal=true
+Type=Application
+Categories=Settings;System;
+StartupWMClass=breadmon

iso/airootfs/etc/skel/.local/share/applications/breadsearch.desktop

@@ -0,0 +1,9 @@
+[Desktop Entry]
+Name=breadsearch
+Comment=Semantic system-wide search
+Exec=breadsearch
+Icon=system-search
+Terminal=false
+Type=Application
+Categories=Utility;
+StartupWMClass=breadsearch