fix: tray icons duplicating and disappearing after session restore

[Dimariqe]

Problem

After resume from suspend (or forced session restore via Hyprland),
some tray icons disappear. Apps that don't detect a StatusNotifierWatcher
restart don't re-register their SNI items, leaving the tray empty.

Additionally, a TrayRecoveryService that scans DBus for unregistered
SNI items after resume could produce duplicate icons because apps
may register their SNI item either via their well-known name
(com.example.AppName/StatusNotifierItem) or via their connection ID
(:1.49/StatusNotifierItem), and the old dedup logic didn't account
for this equivalence.

Root causes

1. Directional blind spot — the well-known name scan and the
   connection-ID scan each only checked their own form against the
   registered items list. If an app registered as :1.49, the
   well-known-name section would still try to register
   com.example.AppName, and vice versa.

2. Case-sensitive SNI Id comparison — some apps report their SNI
   Id property in a different case than their well-known name
   (e.g. "exampleapp" vs "com.example.ExampleApp/...").
   grep -qF never matched, so the fallback dedup check was silently
   skipped every time.

Solution

Add TrayRecoveryService — a singleton that fires 3 seconds after
resume and scans DBus for SNI items that need re-registration.

Key design decisions:

• Unified REGISTERED_CONN_IDS set built upfront by resolving
  every currently registered item (regardless of whether it was
  registered as a well-known name or a connection ID) to its canonical
  :1.xxx connection ID. This is the single source of truth used by
  both scan sections.
• Well-known name section first checks REGISTERED_CONN_IDS via
  the name's connection ID before probing — skips apps already covered
  by a connection-ID registration.
• After registering via well-known name, REGISTERED_CONN_IDS is
  updated immediately so the connection-ID section running next won't
  probe the same app again in the same recovery pass.
• Connection-ID section uses REGISTERED_CONN_IDS as its primary
  gate, with a case-insensitive SNI Id string match as a secondary
  fallback inside each parallel subshell.
• Single busctl snapshot (BUSCTL_OUT) is taken once and reused
  across both sections, replacing two redundant dbus-send ListNames
  calls.

[bbedward]

This is nice, though I think we could just integrate it into DMS server, and not need any additional QML for it. That might be a better approach since it's already hooked in to everything.

[Dimariqe]

I'll be back with a Go implementation.