Bump to v1.7.0: self-updater release-filtering fix

The client and the relay server are published from the same GitHub repo;
the server's releases use "server-" prefixed tags. RemSoundUpdater hit
/releases/latest, which is repo-wide — when a server release was newest,
the updater fed "server-v2.3" to ParseTag (-> a bogus 0.0.3) and concluded
"up to date", silently skipping real client updates.

CheckForUpdateAsync now lists /releases and picks the highest-versioned
release whose tag is a RemSound client tag (new IsClientReleaseTag: after
an optional leading "v", first char must be a digit). Drafts and
pre-releases are skipped. The server-side updater already filters to
"server-" tags, so client + server coexist in one repo cleanly.

Also rewrites build-release.ps1 with a data-safety check: it publishes to
a fresh staging folder and aborts the release if any logs/, profiles/,
recordings/ folder, .log file or remsound.config.json is present in the
staged output or the finished zip — preventing a repeat of the v1.5/v1.6
zips that shipped with developer logs and profiles.

No wire-format or audio-pipeline changes — v1.5/v1.6/v1.7 interoperate.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/RemSound.App/AboutDialog.cs

@@ -20,6 +20,23 @@ internal sealed class AboutDialog : Form
     /// updates" path.</summary>
     private const string ReleaseNotes =
         """
+        RemSound v1.7
+
+        Updater fix. No wire-format or audio-pipeline changes —
+        v1.5, v1.6 and v1.7 peers interoperate.
+
+        Bug fix:
+          * Check for updates now reliably finds RemSound
+            releases. RemSound and the relay server share one
+            GitHub repository; the server's releases use
+            "server-" tags. The updater previously looked only
+            at the single newest release of any kind, so a
+            server release could derail it (it would misread
+            the version and report "up to date"). It now scans
+            the release list and considers only RemSound client
+            versions, ignoring server releases, drafts and
+            pre-releases.
+
         RemSound v1.6
 
         Three reliability fixes. No wire-format or audio-pipeline