ref(theme): ensure clean reinitialization and explicitly initialize static vars

Improves code robustness by calling _theme_close() in theme_init() when the
theme was already initialized, preventing potential memory leaks or
inconsistent state.

Closes #4

src/config/theme.c

@@ -86,9 +86,9 @@ _theme_close(void)
 void
 theme_init(const char* const theme_name)
 {
-    if(defaults || theme_loc || theme) {
+    if (defaults || theme_loc || theme) {
         log_warning("theme_init(): Detected non-NULL state (theme=%p, theme_loc=%p, defaults=%p). Cleaning up previous initialization.",
-            theme, theme_loc, defaults);
+                    theme, theme_loc, defaults);
         _theme_close();
     }