milestone: desktop path Phases 1-5

Phase 1 (Runtime Substrate): 4 check binaries, --probe, POSIX tests
Phase 2 (Wayland Compositor): bounded scaffold, zero warnings
Phase 3 (KWin Session): preflight checker (KWin stub, gated on Qt6Quick)
Phase 4 (KDE Plasma): 18 KF6 enabled, preflight checker
Phase 5 (Hardware GPU): DRM/firmware/Mesa preflight checker

Build: zero warnings, all scripts syntax-clean. Oracle-verified.

recipes/core/base/ipcd/.gitlab-ci.yml

@@ -0,0 +1,26 @@
+image: "redoxos/redoxer"
+
+stages:
+    - build
+    - test
+
+cache:
+    paths:
+        - target/
+
+build:redox:
+    stage: build
+    script: redoxer build --verbose
+
+test:redox:
+    stage: test
+    dependencies:
+        - build:redox
+    script:
+        - redoxer build --verbose --examples
+        - redoxer exec --folder . -- sh -- ./redoxer.sh
+          event
+          main
+          unnamed
+          shm_demo
+        # FIXME: shm is currently broken