D-Bus Phase 3/4: upgrade sessiond, services, add StatusNotifierWatcher, consolidate configs

- redbear-sessiond: add Manager.Inhibit (pipe FD), CanPowerOff/CanReboot/
  CanSuspend/CanHibernate/CanHybridSleep/CanSleep (return na), PowerOff/
  Reboot/Suspend stubs, GetSessionByPID, ListUsers, ListSeats,
  ListInhibitors, ActivateSession/LockSession/UnlockSession/TerminateSession
- redbear-sessiond: add Session SetIdleHint, SetLockedHint, SetType,
  Terminate methods; wire PauseDevice/ResumeDevice/Lock/Unlock signal
  emission via SignalEmitter injection; add dynamic device enumeration
  scanning /scheme/drm/card* and /dev/input/event* at startup
- redbear-sessiond: replace infinite pending() with stoppable shutdown
  via tokio watch channel + control socket shutdown command
- redbear-upower: add Changed signal emission with 30s periodic polling
  and power state snapshot comparison
- redbear-notifications: add ActionInvoked signal, expand capabilities
  to body + body-markup + actions
- redbear-polkit, redbear-udisks: replace pending() with stoppable
  shutdown via signal handling + watch channel
- Add redbear-statusnotifierwatcher: new session bus service implementing
  org.freedesktop.StatusNotifierWatcher for KDE system tray
- Add D-Bus activation file for StatusNotifierWatcher
- KWin session.cpp: try LogindSession before NoopSession fallback
- Consolidate config profiles: remove obsolete redbear-desktop, redbear-kde,
  redbear-live-*, redbear-minimal-*, redbear-wayland configs; simplify
  to three supported targets (redbear-full, redbear-mini, redbear-grub)
- Update DBUS-INTEGRATION-PLAN.md and DESKTOP-STACK-CURRENT-STATUS.md
  with Phase 3/4 fragility assessment, KWin readiness matrix, and
  completeness gap analysis

local/recipes/kde/kwin/source/src/core/session.cpp

@@ -24,9 +24,6 @@ static const struct
 
 std::unique_ptr<Session> Session::create()
 {
-#ifdef Q_OS_REDOX
-    return NoopSession::create();
-#else
     for (const auto &sessionInfo : s_availableSessions) {
         std::unique_ptr<Session> session = sessionInfo.createFunc();
         if (session) {
@@ -34,20 +31,19 @@ std::unique_ptr<Session> Session::create()
         }
     }
     return nullptr;
-#endif
 }
 
 std::unique_ptr<Session> Session::create(Type type)
 {
 #ifdef Q_OS_REDOX
-    switch (type) {
-    case Type::Logind:
-        return NoopSession::create();
-    case Type::ConsoleKit:
-        return ConsoleKitSession::create();
-    case Type::Noop:
-        return NoopSession::create();
+    for (const auto &sessionInfo : s_availableSessions) {
+        if (sessionInfo.type == type) {
+            if (auto session = sessionInfo.createFunc()) {
+                return session;
+            }
+        }
     }
+    return NoopSession::create();
 #else
     for (const auto &sessionInfo : s_availableSessions) {
         if (sessionInfo.type == type) {