fix(editor): prevent UI redraw conflicts during editor suspend/resume

Guard against re-entrant editor launches, abort editor on Ctrl-Z,
and centralize suspend-aware redraws through prof_doupdate() to prevent
terminal corruption when SIGTSTP is received while editor is active.

Removes SIGUSR1 editor escape in favor of standard pkill <editor> recovery.

src/tools/editor.c

@@ -32,9 +32,15 @@ typedef struct EditorContext
     void* user_data;
 } EditorContext;
 
+static gboolean editor_active = FALSE; // re-entrancy guard
+static pid_t editor_pid = 0;
+
 static void
 _editor_exit_cb(GPid pid, gint status, gpointer data)
 {
+    editor_active = FALSE;
+    editor_pid = 0;
+
     EditorContext* ctx = data;
     gchar* contents = NULL;
     GError* error = NULL;
@@ -52,8 +58,10 @@ _editor_exit_cb(GPid pid, gint status, gpointer data)
             cons_show_error("Could not read edited content: %s", error->message);
             g_error_free(error);
         }
-    } else {
-        cons_show_error("Editor exited with error status %d", WEXITSTATUS(status));
+    } else if (WIFEXITED(status)) {
+        cons_show_error("Editor exited with status %d", WEXITSTATUS(status));
+    } else if (WIFSIGNALED(status)) {
+        cons_show("Editor session cancelled.");
     }
 
     if (remove(ctx->filename) != 0) {
@@ -70,6 +78,11 @@ _editor_exit_cb(GPid pid, gint status, gpointer data)
 gboolean
 launch_editor(gchar* initial_content, void (*callback)(gchar* content, void* data), void* user_data)
 {
+    if (editor_active) {
+        cons_show_error("An editor session is already active.");
+        return TRUE;
+    }
+
     auto_gchar gchar* filename = NULL;
     auto_gerror GError* glib_error = NULL;
     const char* jid = connection_get_barejid();
@@ -118,6 +131,7 @@ launch_editor(gchar* initial_content, void (*callback)(gchar* content, void* dat
     ctx->callback = callback;
     ctx->user_data = user_data;
 
+    editor_active = TRUE;
     ui_suspend();
 
     // Force GLib to install its SIGCHLD handler before forking. Creating a
@@ -129,6 +143,7 @@ launch_editor(gchar* initial_content, void (*callback)(gchar* content, void* dat
     pid_t pid = fork();
     if (pid == -1) {
         log_error("[Editor] Failed to fork: %s", strerror(errno));
+        editor_active = FALSE;
         ui_resume();
         ui_resize();
         cons_show_error("Failed to start editor: %s", strerror(errno));
@@ -139,7 +154,8 @@ launch_editor(gchar* initial_content, void (*callback)(gchar* content, void* dat
     } else if (pid == 0) {
         // Child process: Inherits TTY from parent
 
-        // Reset signal handlers that profanity sets so the editor doesn't inherit them
+        // SIGTSTP=SIG_DFL lets vim's :stop / Ctrl-Z work; profanity catches
+        // the STOPPED state via editor_check_stopped() and drops to the shell.
         signal(SIGINT, SIG_DFL);
         signal(SIGTSTP, SIG_DFL);
         signal(SIGPIPE, SIG_DFL);
@@ -151,7 +167,39 @@ launch_editor(gchar* initial_content, void (*callback)(gchar* content, void* dat
     }
 
     // Parent process: Watch the child asynchronously
+    editor_pid = pid;
     g_child_watch_add((GPid)pid, _editor_exit_cb, ctx);
     g_strfreev(editor_argv);
     return FALSE;
 }
+
+void
+editor_emergency_kill(void)
+{
+    if (!editor_active || editor_pid <= 0) {
+        return;
+    }
+    log_warning("[Editor] aborting editor pid %d", editor_pid);
+    kill(editor_pid, SIGCONT); // wake if STOPPED; no-op otherwise
+    kill(editor_pid, SIGTERM);
+    // _editor_exit_cb will restore the UI when the child reaps.
+}
+
+gboolean
+editor_is_active(void)
+{
+    return editor_active;
+}
+
+gboolean
+editor_check_stopped(void)
+{
+    // Poll for STOPPED without reaping (g_child_watch handles exit via its
+    // own WNOHANG). Lets prof_run drop the group to the shell on Ctrl-Z.
+    if (!editor_active || editor_pid <= 0) {
+        return FALSE;
+    }
+    int status;
+    pid_t r = waitpid(editor_pid, &status, WNOHANG | WUNTRACED);
+    return (r == editor_pid && WIFSTOPPED(status));
+}