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

Makefile.am

@@ -185,6 +185,7 @@ functionaltest_sources = \
 	tests/functionaltests/test_software.c tests/functionaltests/test_software.h \
 	tests/functionaltests/test_muc.c tests/functionaltests/test_muc.h \
 	tests/functionaltests/test_disconnect.c tests/functionaltests/test_disconnect.h \
+	tests/functionaltests/test_lastactivity.c tests/functionaltests/test_lastactivity.h \
 	tests/functionaltests/functionaltests.c
 
 main_source = src/main.c