Release v4.7: keep trying your configured peer after a reboot (#15)

Removes the heartbeat "adopt a live address" feature (added v1.6). On a LAN with
more than one RemSound machine it could latch a receiver onto an unrelated sender
that happened to be pinging the audio port — then never recover to the real peer,
needing a manual restart (the singer's #15, with log). The feature guessed peer
identity from an untracked ping source with no way to verify it was the same peer;
on the stable VPN/LAN addresses RemSound is actually used with, it only ever caused
harm, since same-address reconnect already works via the continuous heartbeat.
Removed TryAdoptLiveHeartbeatAddress + IsPrivateLanAddress (MainForm) and
GetUntrackedPingSources + recentPingSources (HeartbeatService); the identity-safe
discovery-based following (by verified peer ID) stays. Manual troubleshooting entry
rewritten to match.

Also bundles the held changes since v4.6: status reads line-by-line with GB totals
and double-press-to-copy, CPU/memory in the status, the Install Scripts folder, and
the what's-new-after-failed-update fix. Version 4.7; About + RELEASE_NOTES updated.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/RemSound.App/AboutDialog.cs

@@ -20,6 +20,35 @@ internal sealed class AboutDialog : Form
     /// updates" path.</summary>
     private const string ReleaseNotes =
         """
+        RemSound v4.7
+
+        Sound now comes back on its own after a reboot.
+
+        If RemSound started before your network or VPN
+        was up, it could latch onto a different machine
+        on your network and stay silent until you closed
+        and reopened it. It now keeps trying the peer you
+        chose and connects the moment it answers — no
+        manual reconnect. (Thank you to the singer who
+        reported this and sent the log that pinned it
+        down.)
+
+        A few improvements for screen-reader users. The
+        "Speak the RemSound status information" hotkey
+        now reads the status a line at a time, shows big
+        data totals in gigabytes, and a quick double
+        press copies the status to the clipboard so you
+        can share it. The status also now includes how
+        much CPU and memory RemSound itself is using.
+
+        If RemSound ever won't start because the .NET
+        runtime is missing, there's a new "Install
+        Scripts" folder next to the program with a
+        one-click installer for it.
+
+        And the "what's new" notes no longer pop up a
+        second time after an update that didn't finish.
+
         RemSound v4.6
 
         Follow your Windows default audio device.