fix: backward-compat + bug fixes and man-page build fix for 0.16.0

Post-0.15.0 review of the 0.15.0..HEAD range surfaced regressions and
bugs. This restores backward compatibility for existing configs/CSS,
fixes confirmed defects, and repairs the scdoc man-page build break on
master. Pango-markup tooltips are intentional and were kept.

Backward-compat restorations:
- AModule: honor legacy numeric Gdk::CursorType cursor values (int overload)
- memory: correct GiB divisor (was ~2.3% low); round bare {} placeholders
- wireplumber: scale max-volume into the linear domain so the cap works again
- idle_inhibitor: gate right/middle-click deactivate & scroll on dynamic-timeouts;
  accept both dynamic-timeout(s); widen timeout to double (no fractional truncation)
- custom: keep #custom-<name>.<class> CSS selectors working (classes on box_)
- image: don't wordexp-split a single path; fall back to the literal path
- niri/window: restore hide-when-empty (new show-empty opt-in); escape tooltip
- wlr/taskbar: plain-text tooltip when markup is disabled

Bug fixes:
- tray: fix use-after-free in onAdd; guard the watcher retry timeout
- hyprland: clamp max-windows iterator (OOB); drop duplicate language tooltip block
- niri/window: supply {col}/{max_col} args in the empty branch (fmt::format_error)
- mpris: escape {dynamic}/{player} tooltip; fix dangling player; albumArtist source
- mango: fix use-after-free race (dispatch under callback_mutex_)
- mpd: contain throwing checkErrors in noexcept idle paths (no std::terminate/UAF)
- keyboard_state: always render every lock label, with guarded defaults
- bluetooth: bound GATT ReadValue timeout, opt-in + services-resolved gating,
  preserve authoritative Battery1 percentage
- wireplumber: fix WpDevice reference leak / NULL handling
- battery, clock, dwl, wayfire, graph, custom_graph, transform, river: assorted
  crash/logic fixes

Man page / build:
- niri-workspaces: fix scdoc "indented by an amount greater than 1"
  (workspace-taskbar sub-options were mis-indented; breaks man-page build)
- document new show-empty (niri/window); correct network {txBitrate}/{rxBitrate}

Not compiled locally (no gtkmm on this host); C++ build relies on CI.
Man pages validated with scdoc 1.11.4.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/modules/sni/tray.cpp

@@ -70,11 +70,14 @@ void Tray::onAdd(std::unique_ptr<Item>& item) {
   }
   items_.push_back(item.get());
 
+  item->event_box.signal_show().connect([this] { dp.emit(); });
+  item->event_box.signal_hide().connect([this] { dp.emit(); });
+
+  // After this point `item` may be erased/invalidated by the ignore-list check;
+  // do not touch it again below.
   spdlog::debug("Tray::onAdd deferred check - checking ignore list");
   host_.checkIgnoreList(ignore_list_, std::bind(&Tray::onRemove, this, std::placeholders::_1));
 
-  item->event_box.signal_show().connect([this] { dp.emit(); });
-  item->event_box.signal_hide().connect([this] { dp.emit(); });
   dp.emit();
 }