fix: address config injection and SIGCHLD handling

- Sanitize account names to prevent GKeyFile config injection by
  blocking special characters like #, \n, and \r.
- Ensure GLib's SIGCHLD handler is initialized before forking
  external editors to prevent zombie processes.
- Add missing error check for OMEMO random key generation.
- Replace hardcoded console tab ID with a named constant.
- Log invalid JIDs safely to prevent potential null pointer issues.

src/tools/editor.c

@@ -121,6 +121,12 @@ launch_editor(gchar* initial_content, void (*callback)(gchar* content, void* dat
 
     ui_suspend();
 
+    // Ensure GLib's SIGCHLD handler is installed before forking to prevent
+    // zombie children if the editor is launched before the main loop starts.
+    GMainContext* main_ctx = g_main_context_default();
+    g_main_context_acquire(main_ctx);
+    g_main_context_release(main_ctx);
+
     pid_t pid = fork();
     if (pid == -1) {
         log_error("[Editor] Failed to fork: %s", strerror(errno));