newXembedHost failure left the private session bus open, leaking an fd
per RegisterStatusNotifierItem on systems without an XEmbed tray. Add a
closeBus helper that logs on close failure and use it at every back-off
path instead of discarding the error.
Shorten over-long godoc/inline comments across the client/ui tray and
services code: drop narrative restatement, legacy-Fyne tangents, and text
already evident from signatures and names. Keep only the non-obvious why
(concurrency/lock ordering, platform quirks, ordering constraints, the
profile-switch state table). No code changes.
The XEmbed tray (panel) can come up after the autostarted UI on minimal
WMs, so the single startup probe added in #6320 could miss a tray that
appears a second or two later, leaving the icon silently absent. Re-probe
for a ~10s grace period in a goroutine, claiming the watcher as soon as a
tray shows up; back off cleanly if none ever appears (headless/Wayland).
Removes the legacy fyne-based client/ui implementation and renames the
Wails replacement (client/ui-wails) to take its place at client/ui. Go
imports, frontend bindings, CI workflows, goreleaser configs and the
windows .syso icon path are updated to follow the rename.
