Release v3.5: USB-card recovery, per-card adaptive buffer, one user folder, audit fixes

- Recover an unplugged/replugged output sound card automatically (issue #5):
  detect the dead WASAPI device and remember the receive-output selection so it
  re-ticks and re-opens when the card returns.
- Adaptive per-card WASAPI buffer target sized to each card's pull chunk, held
  stable so it never flits about under CPU/network load.
- Consolidate all per-user data (config, profiles, logs, sounds) into one
  "user settings and logs" folder; migrate every older layout; exclude it from
  the updater so custom cue sounds now survive updates.
- Mic-privacy detector: warn once when a Windows-blocked mic is switched on, or a
  profile loads with one already on.
- All warning/notice dialogs now come to the foreground even when minimised.
- Apply volume + mute on profile load (were saved but not restored).
- Crash-safe (atomic) profile/config saves.
- Fix two resource leaks (push-mode capture MMDevice; UPnP DeviceFound handler).
- Remove dead code (baseline-diff machinery, dead ASIO probes, no-op stubs).
- Docs: readme.html, MANUAL.md, About-box changelog and release notes for v3.5.

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

src/RemSound.App/AboutDialog.cs

@@ -20,6 +20,37 @@ internal sealed class AboutDialog : Form
     /// updates" path.</summary>
     private const string ReleaseNotes =
         """
+        RemSound v3.5
+
+        Recover a sound card you unplug: if a USB sound card
+        you're listening through is pulled out and plugged back
+        in, RemSound re-opens it on its own and audio resumes —
+        no need to re-tick it.
+
+        Each sound card now gets the right audio cushion
+        automatically. RemSound sizes it to the card, so one that
+        needs a little more gets it without any fiddling, and a
+        fast card stays tight.
+
+        A microphone-privacy heads-up: if Windows is blocking
+        microphone access and you switch a mic on, RemSound warns
+        you once, so you're not left wondering why no one can
+        hear you.
+
+        Warnings always come to the front now, even when RemSound
+        is tucked away in the system tray — so you never miss one.
+
+        Everything this machine keeps for you — settings,
+        profiles, logs and your cue sounds — now lives in one
+        tidy folder called "user settings and logs". It moves
+        there automatically the first time you run this version.
+        From now on, updates never touch that folder, so any
+        custom cue sounds you put there are safe.
+
+        Also: your volume and mute now come back correctly when
+        you load a profile, plus a batch of under-the-hood
+        reliability and tidy-up work.
+
         RemSound v3.4
 
         Quick profile switch: a new global hotkey pops up a