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/host.cpp

@@ -143,12 +143,24 @@ void Host::proxyReady(GObject* src, GAsyncResult* res, gpointer data) {
     // Store the timeout connection so it is disconnected in ~Host, avoiding a
     // use-after-free if the Host is destroyed before the retry fires.
     host->retry_connection_ = Glib::signal_timeout().connect(
-        [host]() {
+        [host]() -> bool {
           if (host->watcher_ != nullptr) {
             return false;
           }
-          auto conn = Gio::DBus::Connection::get_sync(Gio::DBus::BusType::BUS_TYPE_SESSION);
-          host->nameAppeared(conn, "org.kde.StatusNotifierWatcher", "");
+          try {
+            auto conn = Gio::DBus::Connection::get_sync(Gio::DBus::BusType::BUS_TYPE_SESSION);
+            host->nameAppeared(conn, "org.kde.StatusNotifierWatcher", "");
+          } catch (const Glib::Error& e) {
+            spdlog::error("Host: retry get_sync failed: {}", static_cast<std::string>(e.what()));
+            if (host->retry_count_ < MAX_RETRIES) {
+              host->retry_count_ += 1;
+              return true;  // re-arm this timer; never let the exception escape
+            }
+            spdlog::warn("Host: giving up on watcher proxy creation after {} retries",
+                         host->retry_count_);
+          } catch (const std::exception& e) {
+            spdlog::error("Host: retry failed: {}", e.what());
+          }
           return false;
         },
         RETRY_DELAY_MS);