Guarantee a trailing newline when writing a conf so appends cannot join the last line

Plugin/unraid/include/config.php

@@ -276,6 +276,14 @@ function vv_read_conf_raw(string $filename): string {
 function vv_write_conf_raw(string $filename, string $content): bool {
     $path = CONF_DIR . '/' . $filename;
     $tmp  = $path . '.vv.tmp';
+
+    // Guarantee the trailing newline. A textarea does not supply one, so saving through the raw
+    // editor left master.conf ending mid-line — and appending is a real pattern here
+    // (conf_upgrade, and the array writers below), so the next `>>` would have joined itself
+    // onto the last setting instead of starting a line. Appended, never stripped: a deliberate
+    // run of blank lines at the end of a conf is the author's business.
+    if ($content !== '' && !str_ends_with($content, "\n")) $content .= "\n";
+
     if (file_put_contents($tmp, $content) === false) return false;
     return rename($tmp, $path);
 }