Service: config dialog + Service menu

Local checkpoint - NOT for public release.

- ServiceProfileDialog: modal 3-tab editor (Audio send / Audio profile / Connectivity)
  reusing the house controls, with a Save and Close / Cancel / Additional options
  button row. Send-only: send-mode chooser + WASAPI outputs/apps + inputs (no "Send
  my audio" toggle, no receive, no ASIO); codec/rate/lock-to-clock; peers add/remove +
  a Set password button. Additional options sub-dialog = play connect/disconnect sound
  + enable service logging. Edits a Profile clone; returns it on OK.
- Service menu in MainForm: status line + Configure / Install / Uninstall / Start / Stop,
  items enabled per live state on drop-down. Install/uninstall confirm then elevate.
  Configure saves the reserved service profile, points AppConfig at it, stores the
  machine-wide logging choice, and restarts a running service to pick up edits.
- ProfileStore.ReservedServiceProfileTitle ("RemSound service"): the service profile
  lives with normal profiles (so the service Loads it) but ListProfileTitles hides it
  from every picker. ServiceControl reuses that single constant.
- Self-test: the service dialog is now in the accessibility audit (constructs cleanly,
  unique mnemonics, all controls named). Gate 20/20.

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

src/RemSound.App/ServiceControl.cs

@@ -18,6 +18,11 @@ public static class ServiceControl
 {
     public const string ServiceName = "RemSoundService";
     public const string DisplayName = "RemSound send-only service";
+
+    /// <summary>Reserved title of the profile the service streams from. Edited only through the service
+    /// config dialog and filtered out of the normal profile picker so it can't be loaded by accident.
+    /// Single source of truth lives in <see cref="RemSound.Core.ProfileStore.ReservedServiceProfileTitle"/>.</summary>
+    public const string ServiceProfileTitle = RemSound.Core.ProfileStore.ReservedServiceProfileTitle;
     public const string Description =
         "Streams this machine's audio to its RemSound peers without a logged-in user (lock screen). " +
         "Send-only; yields to the interactive RemSound app while it is open.";