mango: show focused window next to tags, fix mmsg lookup, 0.15.x compat

- new focused-window block ({icon} {app_id} - {title}) driven by the
  active_client field of mmsg watch all-monitors (mangowm >= 0.14)
- resolve program icons via freedesktop icon themes/.desktop files
  (new icon module, cairo png feature, cached per app_id)
- new show_focused_window config option (default true)
- run mmsg from PATH instead of hardcoded /usr/bin/mmsg (broken on NixOS)
- handle null active_client fields (no focused client) without failing
  to parse the whole event
- drop stale TODO comment and unused variable in mango provider
- add .justfile run recipe exporting MANGO_INSTANCE_SIGNATURE

1 files changed, 2 insertions, 0 deletions

diff --git a/src/config.rs b/src/config.rs
index f54e2ed..e5c04e7 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -46,6 +46,7 @@ pub struct Config {
     pub invert_touchpad_scrolling: bool,
     pub show_tags: bool,
     pub show_layout_name: bool,
+    pub show_focused_window: bool,
     pub blend: bool,
     pub show_mode: bool,
     pub start_hidden: bool,
@@ -92,6 +93,7 @@ impl Default for Config {
             invert_touchpad_scrolling: true,
             show_tags: true,
             show_layout_name: true,
+            show_focused_window: true,
             blend: true,
             show_mode: true,
             start_hidden: false,