Bump to v3.1.2: tray icon re-stamps on state change, recording shows as a flag

- Tray icon now re-registers itself (hide+re-show) whenever the meaningful
  state changes — peer connect/drop, send/receive toggle, recording
  start/stop — so the name a screen reader announces stays in step with
  the live state. Fixes the persistent "no peers" then "1 peer" double
  announcement that the old "show window then minimise again" trick used
  to clear by hand. Same root cause as the v3.1.1 stuck-tooltip fix, just
  exposed when the state changes a moment after the icon appears.
- Recording shows as a plain "recording" flag in the tray rather than a
  live timer. A ticking timer would have either flickered the icon once a
  second or left a screen reader announcing a stale time next to the live
  one. Removed the now-dead FormatRecordingElapsed helper.
- Bundles the earlier Win7 updater fix (6cbde0d): a failed secure
  connection is no longer mislabelled as "you're up to date".
- About box, RELEASE_NOTES.md, readme.html and MANUAL.md updated to match.

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

src/RemSound.App/MainForm.cs

@@ -5292,14 +5292,15 @@ public sealed class MainForm : Form
                 if (ph.State == PeerHealthState.Healthy) healthyPeers++;
             }
         }
-        // Recording timer — only included when a recording is actually running. Slots in
-        // right after the "RemSound" leader as Ed asked, so it reads as a status on the
-        // app itself rather than a property of the peer list.
-        string? recordingPart = null;
-        if (recordingController.IsRecording && recordingController.RecordingStartedUtc is { } startedUtc)
-        {
-            recordingPart = $"recording for {FormatRecordingElapsed(DateTime.UtcNow - startedUtc)}";
-        }
+        // Recording status — a plain "recording" flag while a capture is running, with no
+        // elapsed timer. A live timer would have to rewrite the tooltip every second, which
+        // fights the tray icon's re-stamp-on-change behaviour: it would either flicker the
+        // icon once a second or leave a screen reader announcing a stale time next to the live
+        // one. Recording starting and stopping are real state changes that re-stamp cleanly;
+        // the second-by-second count is intentionally left to the main window. Slots in right
+        // after the "RemSound" leader so it reads as a status on the app itself rather than a
+        // property of the peer list.
+        string? recordingPart = recordingController.IsRecording ? "recording" : null;
         if (healthyPeers == 0 && !sendMyAudioCheckbox.Checked && !receiveAudioCheckbox.Checked)
         {
             return recordingPart is null
@@ -5346,20 +5347,6 @@ public sealed class MainForm : Form
         return list.CheckedItems.Count > 0;
     }
 
-    /// <summary>Compact duration formatter for the tray tooltip's "recording for X" segment.
-    /// Under an hour shows MM:SS; from an hour on it shows H:MM:SS — the same shape Windows
-    /// uses for media-player elapsed-time displays, so it reads naturally to people who
-    /// don't otherwise know it's a custom format.</summary>
-    private static string FormatRecordingElapsed(TimeSpan elapsed)
-    {
-        // Negative elapsed (clock skew across a sleep cycle) gets clamped to zero — better
-        // than displaying "-00:01" mid-tooltip.
-        if (elapsed < TimeSpan.Zero) elapsed = TimeSpan.Zero;
-        return elapsed.TotalHours >= 1
-            ? $"{(int)elapsed.TotalHours}:{elapsed.Minutes:D2}:{elapsed.Seconds:D2}"
-            : $"{elapsed.Minutes:D2}:{elapsed.Seconds:D2}";
-    }
-
     /// <summary>Pretty-print "WASAPI", "ASIO", "WASAPI + ASIO", or "no devices" depending
     /// on which of the two flags are set. "no devices" covers the awkward case where the
     /// user has the send/receive checkbox on but hasn't ticked anything for the engine to