fix(tools.func): remove dangerous trap in create_temp_dir()

The EXIT/ERR/INT/TERM trap inside create_temp_dir() overwrites any
global traps and fires when the shell exits, not when the calling
function returns. Since the function is a utility that returns a path
via stdout, the trap fires immediately on function return and cannot
properly clean up the caller's temp dir. Callers already handle their
own cleanup via explicit rm -rf.

misc/tools.func

@@ -282,7 +282,7 @@ get_cached_version() {
     cat "/var/cache/app-versions/${app}_version.txt"
     return 0
   fi
-  return 0
+  return 1
 }
 
 # ------------------------------------------------------------------------------
@@ -1100,8 +1100,9 @@ get_system_arch() {
 # ------------------------------------------------------------------------------
 create_temp_dir() {
   local tmp_dir=$(mktemp -d)
-  # Set trap to cleanup on EXIT, ERR, INT, TERM
-  trap "rm -rf '$tmp_dir'" EXIT ERR INT TERM
+  # Callers should handle their own cleanup (rm -rf "$tmpdir")
+  # Do NOT set trap here — it would overwrite global traps and only fire
+  # when create_temp_dir() itself returns, not the calling function
   echo "$tmp_dir"
 }
 
@@ -5351,7 +5352,7 @@ function setup_java() {
       "main"
   fi
 
-  # Get currently installed version
+  # Get currently installed version (use dpkg-query to avoid column truncation)
   local INSTALLED_VERSION=""
   INSTALLED_VERSION=$(dpkg-query -W -f '${Package}\n' 2>/dev/null | grep -oP '^temurin-\K[0-9]+(?=-jdk$)' | head -n1 || echo "")
 
@@ -7832,8 +7833,8 @@ function setup_uv() {
   local TMP_DIR=$(mktemp -d)
   local CACHED_VERSION
 
-  # trap for TMP Cleanup
-  trap "rm -rf '$TMP_DIR'" EXIT
+  # trap for TMP Cleanup (RETURN instead of EXIT to avoid overwriting global traps)
+  trap "rm -rf '$TMP_DIR'" RETURN
 
   CACHED_VERSION=$(get_cached_version "uv")
 
@@ -8103,6 +8104,8 @@ function setup_docker() {
   local docker_installed=false
   local portainer_installed=false
   local USE_DOCKER_REPO="${USE_DOCKER_REPO:-false}"
+  local DOCKER_CURRENT_VERSION=""
+  local DOCKER_LATEST_VERSION=""
 
   # Check if Docker is already installed
   if command -v docker &>/dev/null; then