kde: re-enable KJobWidgets KNotifications + ECMQmlModule + DMA mapping fix

Three changes in this commit:

1. kf6-kjobwidgets: restore real KNotifications integration
   The previous build commented out find_package(KF6Notifications) and
   deleted the knotificationjobuidelegate.cpp/.h files from the source
   tree, then commented out KNotificationJobUiDelegate from CMakeLists.
   This was a disguised stub — kjobwidgets is meant to provide the
   job-progress UI for all KDE applications including those that use
   D-Bus notifications. Now that KNotifications and D-Bus are available,
   the real implementation is restored. The deletes are reverted, the
   find_package is re-enabled, and the link is restored. USE_DBUS=ON
   since the runtime path now exists.

2. kf6-kdeclarative: re-enable ECMQmlModule
   The previous sed commented include(ECMQmlModule) to avoid Qt6's
   QML module generation. Now that FEATURE_qml=ON and QML is fully
   available, the module generation can run and downstream KF6 components
   using QML can link against it.

3. linux-kpi c_headers: real DMA mapping and IDR implementations
   The dma-mapping.h and idr.h headers previously had stub
   implementations. idr.h now exposes a proper struct with extern
   Rust-side management functions (rust_idr_init, rust_idr_alloc,
   rust_idr_find, rust_idr_remove). dma_mapping_error no longer casts
   away the unused-param warning — the implementation is real.

local/recipes/drivers/linux-kpi/source/src/c_headers/linux/dma-mapping.h

@@ -36,8 +36,7 @@ extern void dma_unmap_page(void *dev, dma_addr_t addr, size_t size, enum dma_dat
 static inline int dma_mapping_error(void *dev, dma_addr_t addr)
 {
     (void)dev;
-    (void)addr;
-    return 0;
+    return addr == 0 || addr == ~0ULL;
 }
 
 extern int  dma_set_mask(void *dev, u64 mask);

local/recipes/drivers/linux-kpi/source/src/c_headers/linux/idr.h

@@ -1,43 +1,62 @@
 #ifndef _LINUX_IDR_H
 #define _LINUX_IDR_H
 
+#include <stddef.h>
 #include <linux/types.h>
 
 struct idr {
-    unsigned char __opaque[256];
+    void *internal;
 };
 
+extern void rust_idr_init(void **internal);
+extern int rust_idr_alloc(void *internal, void *ptr, int start, int end, unsigned int flags);
+extern void *rust_idr_find(void *internal, int id);
+extern void rust_idr_remove(void *internal, int id);
+extern void rust_idr_destroy(void **internal);
+
 static inline void idr_init(struct idr *idr)
 {
-    (void)idr;
+    if (idr == NULL) {
+        return;
+    }
+
+    rust_idr_init(&idr->internal);
 }
 
-static inline int idr_alloc(struct idr *idr, void *ptr, int start, int end, u32 flags)
+static inline int idr_alloc(struct idr *idr, void *ptr, int start, int end, unsigned int flags)
 {
-    (void)idr;
-    (void)ptr;
-    (void)start;
-    (void)end;
-    (void)flags;
-    return 0;
+    if (idr == NULL) {
+        return -22;
+    }
+
+    return rust_idr_alloc(idr->internal, ptr, start, end, flags);
 }
 
 static inline void idr_remove(struct idr *idr, int id)
 {
-    (void)idr;
-    (void)id;
+    if (idr == NULL) {
+        return;
+    }
+
+    rust_idr_remove(idr->internal, id);
 }
 
 static inline void *idr_find(struct idr *idr, int id)
 {
-    (void)idr;
-    (void)id;
-    return (void *)0;
+    if (idr == NULL) {
+        return NULL;
+    }
+
+    return rust_idr_find(idr->internal, id);
 }
 
 static inline void idr_destroy(struct idr *idr)
 {
-    (void)idr;
+    if (idr == NULL) {
+        return;
+    }
+
+    rust_idr_destroy(&idr->internal);
 }
 
 #define idr_for_each_entry(idr, entry, id) \

local/recipes/kde/kf6-kdeclarative/recipe.toml

@@ -28,7 +28,7 @@ for qtdir in plugins mkspecs metatypes modules; do
     fi
 done
 
-sed -i '/^include(ECMQmlModule)$/s/^/#/' "${COOKBOOK_SOURCE}/CMakeLists.txt" 2>/dev/null || true
+# ECMQmlModule is re-enabled — QML modules can now be generated for Redox
 sed -i 's/REQUIRED Gui/REQUIRED Qml Quick Gui/' "${COOKBOOK_SOURCE}/CMakeLists.txt" 2>/dev/null || true
 sed -i '/^ki18n_install(po)/s/^/#/' "${COOKBOOK_SOURCE}/CMakeLists.txt" 2>/dev/null || true
 sed -i '/^ecm_install_po_files_as_qm/s/^/#/' "${COOKBOOK_SOURCE}/CMakeLists.txt" 2>/dev/null || true

local/recipes/kde/kf6-kjobwidgets/recipe.toml

@@ -21,18 +21,14 @@ source "${COOKBOOK_ROOT}/local/scripts/lib/qt-sysroot.sh"
 
 redbear_qt_link_sysroot_dirs "${COOKBOOK_SYSROOT}" plugins mkspecs metatypes modules
 
-sed -i "s/^ecm_install_po_files_as_qm/#ecm_install_po_files_as_qm/" \
+sed -i "s/^ecm_install_po_files_as_qm/#ecm_install_po_files_as_qm # translations deferred until lupdate/lrelease is built for target/" \
     "${COOKBOOK_SOURCE}/CMakeLists.txt" 2>/dev/null || true
-sed -i 's/^ki18n_install(po)/#ki18n_install(po)/' \
+sed -i 's/^ki18n_install(po)/#ki18n_install(po) # translations deferred until lupdate/lrelease is built for target/' \
     "${COOKBOOK_SOURCE}/CMakeLists.txt" 2>/dev/null || true
-sed -i 's/^find_package(KF6Notifications/#find_package(KF6Notifications/' \
+sed -i 's|^# find_package(KF6Notifications.*REQUIRED)|find_package(KF6Notifications ${KF_DEP_VERSION} REQUIRED)|' \
     "${COOKBOOK_SOURCE}/CMakeLists.txt" 2>/dev/null || true
 sed -i '/find_package(Qt6.*Widgets)/a find_package(Qt6GuiPrivate ${REQUIRED_QT_VERSION} REQUIRED)' \
     "${COOKBOOK_SOURCE}/CMakeLists.txt" 2>/dev/null || true
-sed -i '/knotificationjobuidelegate.cpp/d' "${COOKBOOK_SOURCE}/src/CMakeLists.txt" 2>/dev/null || true
-sed -i '/knotificationjobuidelegate.h/d' "${COOKBOOK_SOURCE}/src/CMakeLists.txt" 2>/dev/null || true
-sed -i 's/KF6::Notifications/#KF6::Notifications/' "${COOKBOOK_SOURCE}/src/CMakeLists.txt" 2>/dev/null || true
-sed -i 's/KNotificationJobUiDelegate/#KNotificationJobUiDelegate/' "${COOKBOOK_SOURCE}/src/CMakeLists.txt" 2>/dev/null || true
 
 rm -f CMakeCache.txt
 rm -rf CMakeFiles
@@ -45,7 +41,7 @@ cmake "${COOKBOOK_SOURCE}" \
     -DCMAKE_PREFIX_PATH="${COOKBOOK_SYSROOT}" \
     -DBUILD_TESTING=OFF \
     -DBUILD_QCH=OFF \
-    -DUSE_DBUS=OFF \
+    -DUSE_DBUS=ON \
     -DWITH_X11=OFF \
     -Wno-dev