Prevent the use of the root folder as workspace (#1052)

Author: frenck

vscode/DOCS.md

@@ -104,6 +104,11 @@ return to the defaults as delivered by this add-on, do the following:
   Although we support ARM devices, please be aware, that this add-on is quite
   heavy to run, and requires quite a bit of RAM. We do not recommended to run
   it on devices with less than 4Gb of memory.
+- **Do not use the root directory (`/`) as your workspace.** Opening the root
+  directory causes severe performance issues, as VS Code will attempt to index
+  the entire filesystem, resulting in excessive CPU and memory usage. Always
+  use `/config` (the default) or another specific directory. The add-on will
+  prevent startup if the root directory is configured as the workspace.
 - "Visual Studio Code is unable to watch for file changes in this large
   workspace" (error ENOSPC)
 

vscode/rootfs/etc/s6-overlay/s6-rc.d/init-code-server/run

@@ -28,6 +28,14 @@ if bashio::config.has_value 'config_path'; then
     if ! bashio::fs.directory_exists "${config_path}"; then
         bashio::exit.nok "Configured config path does not exists"
     fi
+    # Prevent using root directory as workspace to avoid performance issues
+    if [[ "${config_path}" == "/" ]]; then
+        bashio::exit.nok \
+            "Using the root directory (/) as workspace is not allowed. " \
+            "This causes severe performance issues as VS Code will index " \
+            "the entire filesystem. Please use /config or another specific " \
+            "directory instead."
+    fi
 fi
 
 # Ensure persistent data folder exists.