Add initial eproc system monitor

- Add the eproc process-monitoring application and persistent window/table state
  - Implement Linux process, network, GPU, icon, and GUI-window collection
  - Add optional process columns, styling, i18n-ready strings, and command copying
  - Retain exited processes for one update and color them as ended
  - Extend table sizing and header behavior for persisted column layouts
  - Organize Linux-specific sources under platform/linux
  - Keep unsupported platforms buildable with a startup WIP warning

.ecode/project_build.json

@@ -417,6 +417,12 @@
         "command": "${project_root}/bin/eepp-ui-application-multi-window-debug",
         "name": "eepp-ui-application-multi-window-debug",
         "working_dir": "${project_root}/bin"
+      },
+      {
+        "args": "",
+        "command": "${project_root}/bin/eproc-debug",
+        "name": "eproc-debug",
+        "working_dir": "${project_root}/bin"
       }
     ],
     "var": {