fix(fireflyiii): respect user-configured DB credentials when using mariadb_addon

When DB_CONNECTION is set to mariadb_addon, the script now checks if the user
has explicitly configured DB_USERNAME, DB_PASSWORD, or DB_DATABASE in addon
options. If set, those values are used instead of the MariaDB addon service
discovery credentials. This fixes authentication failures when the service
account doesn't have proper access.

Fixes: Firefly III access denied for user 'service' issue

Agent-Logs-Url: https://github.com/alexbelgium/hassio-addons/sessions/7cacda5b-d03e-47c5-b4fc-4cfb4ef2a3dc

Co-authored-by: alexbelgium <44178713+alexbelgium@users.noreply.github.com>

fireflyiii/rootfs/etc/cont-init.d/99-run.sh

@@ -90,9 +90,26 @@ case $(bashio::config 'DB_CONNECTION') in
         DB_CONNECTION=mysql
         DB_HOST=$(bashio::services "mysql" "host")
         DB_PORT=$(bashio::services "mysql" "port")
-        DB_DATABASE=firefly
-        DB_USERNAME=$(bashio::services "mysql" "username")
-        DB_PASSWORD=$(bashio::services "mysql" "password")
+
+        # Use user-configured database name if provided, otherwise default to 'firefly'
+        if bashio::config.has_value "DB_DATABASE"; then
+            DB_DATABASE=$(bashio::config "DB_DATABASE")
+        else
+            DB_DATABASE=firefly
+        fi
+
+        # Use user-configured credentials if provided, otherwise use service discovery
+        if bashio::config.has_value "DB_USERNAME"; then
+            DB_USERNAME=$(bashio::config "DB_USERNAME")
+        else
+            DB_USERNAME=$(bashio::services "mysql" "username")
+        fi
+        if bashio::config.has_value "DB_PASSWORD"; then
+            DB_PASSWORD=$(bashio::config "DB_PASSWORD")
+        else
+            DB_PASSWORD=$(bashio::services "mysql" "password")
+        fi
+
         export DB_CONNECTION
         export DB_HOST && bashio::log.blue "DB_HOST=$DB_HOST"
         export DB_PORT && bashio::log.blue "DB_PORT=$DB_PORT"
@@ -110,7 +127,7 @@ case $(bashio::config 'DB_CONNECTION') in
             --skip-ssl \
             -u "${DB_USERNAME}" -p"${DB_PASSWORD}" \
             -h "${DB_HOST}" -P "${DB_PORT}" \
-            -e "CREATE DATABASE IF NOT EXISTS \`firefly\`;"
+            -e "CREATE DATABASE IF NOT EXISTS \`${DB_DATABASE}\`;"
         ;;
 
         # Use remote