plasma-desktop: provide XCB with SHM and IMAGE components

plasma-desktop's CMakeLists.txt:223 does
  find_package(XCB REQUIRED COMPONENTS XCB SHM IMAGE)
and configure aborted with "Could NOT find XCB (missing: XCB_LIBRARIES XCB SHM
IMAGE)" -- libxcb was promoted but plasma-desktop did not depend on it, so it
was absent from that recipe's sysroot.

libxcb supplies xcb and xcb-shm (libxcb-shm.a confirmed staged); IMAGE comes
from xcb-util-image, which needs xcb-util. Both promoted out of recipes/wip/x11
and their tarballs fetched and blake3-verified.

This is the case for xcb on Wayland, not X11 nostalgia: KDE's XWayland
integration and Qt's xcb platform plugin both reference these.

config/redbear-full.toml

@@ -290,6 +290,8 @@ libxfixes = {}
 libxi = {}
 libxrender = {}
 libxft = {}
+xcb-util = {}
+xcb-util-image = {}
 # libice/libsm deliberately NOT included: they are X11 session-management
 # libraries used only by ksmserver, which is inside if(WITH_X11) and is not
 # built. They also need xorg util-macros, which is in no recipe here -- so

local/recipes/kde/plasma-desktop/recipe.toml

@@ -13,6 +13,14 @@ path = "source"
 [build]
 template = "custom"
 dependencies = [
+    # XCB with SHM and IMAGE components: CMakeLists.txt:223
+    # find_package(XCB REQUIRED COMPONENTS XCB SHM IMAGE). libxcb supplies
+    # xcb and xcb-shm; IMAGE comes from xcb-util-image (which needs xcb-util).
+    # Needed even on Wayland -- KDE's XWayland integration and Qt's xcb
+    # platform plugin both reference it.
+    "libxcb",
+    "xcb-util",
+    "xcb-util-image",
     "plasma-workspace",
     "qtbase",
     "qtdeclarative",