fix(ui,db): harden NULL handling and resource lifecycle across UI and SQLite

ui/window: fix subwindow lifecycle (safe delwin on recreate), clamp widths, add fallback timestamp
when loading history to avoid NULL deref
ui/buffer: add GSList bounds checks; assert non-NULL timestamps when creating entries
ui/titlebar: guard newwin failures; make draw/resize/free no-ops when window is NULL
ui/statusbar: guard window creation/resize/close; clamp columns; fallback display name if JID
parsing fails
ui/inputwin: check newpad result; guard resize/getters/close on NULL; safe delwin
ui/chatwin: guard buffer_get_entry/time before ISO8601 formatting
ui/window_list: validate win_create_* results; don’t insert NULL windows; fix barejid leak in
wins_get_by_string
db/database: ensure cleanup on sqlite init/open failures; use sqlite3_close_v2 and warn if busy;
always return a ProfMessage from log_database_get_limits_info and set current UTC timestamp when
is_last with no row; initialize err_msg and free consistently; improve error messages
Prevents crashes from NULL dereferences (e.g., during MAM history) and closes small leaks; improves
robustness under OOM and allocation failures.

src/ui/inputwin.c

@@ -163,6 +163,10 @@ create_input_window(void)
     rl_callback_handler_install(NULL, _inp_rl_linehandler);
 
     inp_win = newpad(1, INP_WIN_MAX);
+    if (!inp_win) {
+        // Failed to allocate input pad; leave inp_win NULL and avoid further use
+        return;
+    }
     wbkgd(inp_win, theme_attrs(THEME_INPUT_TEXT));
     keypad(inp_win, TRUE);
     wmove(inp_win, 0, 0);
@@ -238,6 +242,9 @@ inp_readline(void)
 void
 inp_win_resize(void)
 {
+    if (!inp_win) {
+        return;
+    }
     int col = getcurx(inp_win);
     int wcols = getmaxx(stdscr);
 
@@ -285,8 +292,10 @@ void
 inp_close(void)
 {
     rl_callback_handler_remove();
-    delwin(inp_win);
-    inp_win = NULL;
+    if (inp_win) {
+        delwin(inp_win);
+        inp_win = NULL;
+    }
     fclose(discard);
     discard = NULL;
 }
@@ -294,6 +303,9 @@ inp_close(void)
 char*
 inp_get_line(void)
 {
+    if (!inp_win) {
+        return NULL;
+    }
     werase(inp_win);
     wmove(inp_win, 0, 0);
     _inp_win_update_virtual();
@@ -318,6 +330,9 @@ inp_set_line(const char* const new_line)
 char*
 inp_get_password(void)
 {
+    if (!inp_win) {
+        return NULL;
+    }
     werase(inp_win);
     wmove(inp_win, 0, 0);
     _inp_win_update_virtual();