build: suppress non-essential packages, fix dbus epoll, add git cache

- Suppress curl and git (non-essential for boot, build issues)
- D-Bus: disable epoll (-Depoll=disabled) for relibc compat
- Cookbook: revert skip-on-missing (broke sysroot install)
- Cache system: git-tracked pkgar in local/cache/pkgar/
- Rebuild progress: redox-driver-sys, iommu, kernel, kf6-ecm, dbus done

recipes/wip/services/dbus/recipe.toml

@@ -12,7 +12,7 @@ dependencies = [
 ]
 template = "meson"
 mesonflags = [
-    "-Depoll=enabled",
+    "-Depoll=disabled",
     "-Dx11_autolaunch=disabled",
     "-Dsystemd=disabled",
     "-Dlaunchd=disabled",