feat(history): nodb backlog (#114)

Implements all open items from the nodb backlog:

statusbar
- PREF_STATUSBAR_SHOW_DBBACKEND (default ON) gates the [sqlite] /
  [flatfile] indicator; toggle via "/statusbar show|hide dbbackend"

/history off|on
- "/history off" now stops persistence as well as hiding history on
  open: sets PREF_DBLOG=off + PREF_CHLOG=false in addition to
  PREF_HISTORY=false
- "/history on" restores persistence (re-enabling PREF_DBLOG=on if
  it was off) and PREF_CHLOG, in addition to PREF_HISTORY=true

/logging
- Removed the "/logging chat on|off" subcommand — chat-log
  persistence is now controlled exclusively by /history; the
  command kept only "/logging group on|off" for MUC logs
- All "use '/logging chat on' to enable" hints replaced with
  "/history on"

/privacy logging
- Single-pass validation across {on, off, redact, flatfile}
- Backend-switching values (on, flatfile) now take effect
  immediately when connected (via log_database_switch_backend),
  matching "/history switch" behaviour; off/redact only flip
  pref bits and keep the live backend open
- Updated help text to reflect runtime switching

/correction off
- win_print_outgoing and win_print_outgoing_with_receipt now gate
  _win_correct on PREF_CORRECTION_ALLOW, matching incoming-msg
  paths. Previously a peer's correction reflected via XEP-0280
  carbons (or the user's own /correct invocation) was applied
  in-buffer regardless of the pref

style
- Two local g_strndup allocations in database_flatfile.c switched
  from char* with manual g_free to auto_gchar gchar*

src/ui/console.c

@@ -1884,6 +1884,12 @@ cons_statusbar_setting(void)
         cons_show("Show tab with no actions (/statusbar)       : OFF");
     }
 
+    if (prefs_get_boolean(PREF_STATUSBAR_SHOW_DBBACKEND)) {
+        cons_show("Show database backend (/statusbar)          : ON");
+    } else {
+        cons_show("Show database backend (/statusbar)          : OFF");
+    }
+
     cons_show("Max tabs (/statusbar)                       : %d", prefs_get_statusbartabs());
 
     gint pref_len = prefs_get_statusbartablen();

src/ui/statusbar.c

@@ -609,6 +609,8 @@ _status_bar_draw_maintext(int pos)
 static int
 _status_bar_draw_dbbackend(int pos)
 {
+    if (!prefs_get_boolean(PREF_STATUSBAR_SHOW_DBBACKEND))
+        return pos;
     if (!active_db_backend || !active_db_backend->name)
         return pos;
 

src/ui/window.c

@@ -1600,7 +1600,7 @@ win_print_outgoing(ProfWin* window, const char* show_char, const char* const id,
     GDateTime* timestamp = g_date_time_new_now_local();
 
     const char* myjid = connection_get_fulljid();
-    if (!_win_correct(window, message, id, replace_id, myjid)) {
+    if (!prefs_get_boolean(PREF_CORRECTION_ALLOW) || !_win_correct(window, message, id, replace_id, myjid)) {
         auto_gchar gchar* outgoing_str = prefs_get_string(PREF_OUTGOING_STAMP);
         _win_printf(window, show_char, 0, timestamp, 0, THEME_TEXT_ME, outgoing_str, myjid, id, "%s", message);
     }
@@ -1747,7 +1747,7 @@ win_print_outgoing_with_receipt(ProfWin* window, const char* show_char, const ch
     receipt->received = FALSE;
 
     const char* myjid = connection_get_fulljid();
-    if (_win_correct(window, message, id, replace_id, myjid)) {
+    if (prefs_get_boolean(PREF_CORRECTION_ALLOW) && _win_correct(window, message, id, replace_id, myjid)) {
         free(receipt); // TODO: probably we should use this in _win_correct()
     } else {
         int y_start_pos = getcury(window->layout->win);