fix(ui,db): harden NULL handling, fix CWE-134, optimize iterations

security(CWE-134): fix format string injections + add CI check
fix(ui): subwindow lifecycle, newwin/newpad guards, fallback timestamps
fix(db): sqlite cleanup on failures, sqlite3_close_v2
fix(xmpp): queued_messages loop, barejid leak
perf(core): g_hash_table_iter_init instead of g_hash_table_get_keys
refactor(ui): CLAMP macro in _check_subwin_width
test: XEP-0012 and XEP-0045 functional tests

Author: jabber.developer2
Closes #58, #85

src/ui/titlebar.c

@@ -73,9 +73,16 @@ void
 create_title_bar(void)
 {
     int cols = getmaxx(stdscr);
+    if (cols <= 0) {
+        cols = 1;
+    }
 
     int row = screen_titlebar_row();
     win = newwin(1, cols, row, 0);
+    if (!win) {
+        // Failed to create title bar window; skip initialization to avoid NULL deref
+        return;
+    }
     wbkgd(win, theme_attrs(THEME_TITLE_TEXT));
     title_bar_console();
     title_bar_set_presence(CONTACT_OFFLINE);
@@ -88,13 +95,18 @@ create_title_bar(void)
 void
 free_title_bar(void)
 {
-    delwin(win);
-    win = NULL;
+    if (win) {
+        delwin(win);
+        win = NULL;
+    }
 }
 
 void
 title_bar_update_virtual(void)
 {
+    if (!win) {
+        return;
+    }
     ProfWin* window = wins_get_current();
     if (window->type != WIN_CONSOLE) {
         if (typing_elapsed) {
@@ -114,7 +126,13 @@ title_bar_update_virtual(void)
 void
 title_bar_resize(void)
 {
+    if (!win) {
+        return;
+    }
     int cols = getmaxx(stdscr);
+    if (cols <= 0) {
+        cols = 1;
+    }
 
     werase(win);
 
@@ -131,6 +149,9 @@ title_bar_resize(void)
 void
 title_bar_console(void)
 {
+    if (!win) {
+        return;
+    }
     werase(win);
     if (typing_elapsed) {
         g_timer_destroy(typing_elapsed);
@@ -192,6 +213,9 @@ title_bar_set_typing(gboolean is_typing)
 static void
 _title_bar_draw(void)
 {
+    if (!win) {
+        return;
+    }
     int pos;
     int maxrightpos;
     ProfWin* current = wins_get_current();