[feature]: drop application src to CFDeskit

CMakeLists.txt

@@ -65,14 +65,11 @@ setup_third_party(
     GIT_REPOSITORY https://github.com/Awesome-Embedded-Learning-Studio/QuarkWidgets.git
     GIT_TAG        v0.1.0)
 
-# Standalone desktop apps. Each ships a standalone executable launched via
-# QProcess. (Historically apps/ had to precede desktop because desktop reused
-# the calculator parser lib defined here; that coupling has been removed -- the
-# desktop core no longer reaches into apps/. apps/ now only needs to precede
-# test/, which it does; the apps-before-desktop ordering below is convention.)
-log_module_start("apps")
-add_subdirectory(apps)
-log_module_end("apps")
+# Standalone desktop apps now live in the separate `CFDeskit` repo
+# (https://github.com/Awesome-Embedded-Learning-Studio/CFDeskit). The main
+# repo no longer compiles apps — they are deployed as prebuilt artifacts into
+# <bin>/../apps/<id>/ at install/runtime, where AppDiscoverer scans them.
+# See apps/README.md for the deployment contract.
 
 log_module_start("desktop")
 add_subdirectory(desktop)

apps/README.md

@@ -0,0 +1,35 @@
+# apps/ — deployment target (no source)
+
+This directory is the **runtime deployment target** for standalone desktop apps.
+App sources no longer live in this repo — they were extracted to the separate
+[`CFDeskit`](https://github.com/Awesome-Embedded-Learning-Studio/CFDeskit)
+repository (calculator, noter, alarm_clock, calendar, system_state).
+
+## Deployment contract
+
+`AppDiscoverer` (in `desktop/ui/components/launcher/`) scans
+`<bin>/../apps/<id>/app.json` at startup. Each app ships as a self-contained
+package:
+
+```
+<active_root>/apps/
+  libquarkwidgets.so            # shared by all apps (rpath $ORIGIN/..)
+  <id>/
+    <id>                        # executable
+    app.json                    # manifest (app_id, display_name, exec, launch_kind)
+```
+
+## How to deploy
+
+Build CFDeskit and install (or copy) its `apps/` tree here:
+
+```bash
+# clean install:
+( cd ~/CFDeskit && cmake --install build --prefix <CFDesktop deploy root> )
+# quick local test against an existing CFDesktop build tree:
+cp -r ~/CFDeskit/build/apps/. <CFDesktop build>/out/build_develop/apps/
+```
+
+Apps resolve `libquarkwidgets.so` via rpath `$ORIGIN/..` and runtime-verify the
+ABI version (`abi_check.hpp`), so the apps' QuarkWidgets version is fully
+decoupled from the desktop's `bin/libquarkwidgets.so`.