fix(secubox): read modules from UCI config instead of RPCD detection

Fixed empty modules page by changing all module iteration to use
UCI config instead of RPCD script detection:

Problem:
- $MODULES was populated by detect_modules() which only returned
  modules with installed RPCD scripts
- When only luci-app-secubox is installed (without individual
  modules), $MODULES was empty
- This caused modules page to show no modules

Solution:
- Changed all functions to iterate through UCI config sections
- Uses: uci show secubox | grep "=module$"
- Now shows ALL modules defined in /etc/config/secubox
- Modules are marked as installed/not installed based on opkg

Functions updated:
- get_modules()
- get_modules_by_category()
- get_dashboard_data()
- get_alerts()
- get_health()
- get_diagnostics()

This allows the modules page to display all available SecuBox
modules even when they're not installed yet.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

luci-app-secubox/root/usr/libexec/rpcd/luci.secubox

@@ -129,9 +129,12 @@ get_modules() {
 	json_init
 	json_add_array "modules"
 
-	config_load secubox
+	config_load secubox 2>/dev/null || true
 
-	for module in $MODULES; do
+	# List all module sections from UCI config
+	local module_sections=$(uci -q show secubox | grep "=module$" | cut -d. -f2 | cut -d= -f1)
+
+	for module in $module_sections; do
 		local name desc category icon color package config
 
 		config_get name "$module" name "$module"
@@ -170,9 +173,12 @@ get_modules_by_category() {
 	json_init
 	json_add_array "modules"
 
-	config_load secubox
+	config_load secubox 2>/dev/null || true
 
-	for module in $MODULES; do
+	# List all module sections from UCI config
+	local module_sections=$(uci -q show secubox | grep "=module$" | cut -d. -f2 | cut -d= -f1)
+
+	for module in $module_sections; do
 		local mod_category
 		config_get mod_category "$module" category "other"
 
@@ -309,15 +315,19 @@ get_health() {
 	json_init
 	json_add_array "checks"
 
+	config_load secubox 2>/dev/null || true
+
+	# List all module sections from UCI config
+	local module_sections=$(uci -q show secubox | grep "=module$" | cut -d. -f2 | cut -d= -f1)
+
 	# Check each installed module
-	for module in $MODULES; do
+	for module in $module_sections; do
 		local is_installed=$(check_module_installed "$module")
 
 		if [ "$is_installed" = "1" ]; then
 			local is_running=$(check_module_running "$module")
 			local name
 
-			config_load secubox
 			config_get name "$module" name "$module"
 
 			local status="ok"
@@ -364,7 +374,9 @@ get_diagnostics() {
 
 	# Modules status
 	json_add_array "modules"
-	for module in $MODULES; do
+	config_load secubox 2>/dev/null || true
+	local module_sections=$(uci -q show secubox | grep "=module$" | cut -d. -f2 | cut -d= -f1)
+	for module in $module_sections; do
 		local is_installed=$(check_module_installed "$module")
 		local is_running=$(check_module_running "$module")
 
@@ -478,7 +490,10 @@ get_alerts() {
 	# Check each installed module for alerts
 	config_load secubox 2>/dev/null || true
 
-	for module in $MODULES; do
+	# List all module sections from UCI config
+	local module_sections=$(uci -q show secubox | grep "=module$" | cut -d. -f2 | cut -d= -f1)
+
+	for module in $module_sections; do
 		local is_installed=$(check_module_installed "$module")
 
 		if [ "$is_installed" = "1" ]; then
@@ -591,7 +606,10 @@ get_dashboard_data() {
 	json_add_array "modules"
 	local total=0 installed=0 running=0
 
-	for module in $MODULES; do
+	# List all module sections from UCI config
+	local module_sections=$(uci -q show secubox | grep "=module$" | cut -d. -f2 | cut -d= -f1)
+
+	for module in $module_sections; do
 		local name desc category icon color
 		config_get name "$module" name "$module"
 		config_get desc "$module" description ""