Release v3.7: device-change smoothing, auto-tune spike rejection, wider mic detector, forensic logging

Coalesce capture-engine rebuilds (CompositeCaptureBackend): a swap-triggering
source change now arms a 250ms debounce timer and re-arms on each further
change, so a flap or quick reconfiguration produces ONE rebuild to the final
state instead of a burst (Andre's 16:40 four-rebuilds-in-33s crackle). In-place
updates still apply immediately; a pending rebuild whose target flaps back is
cancelled.

Auto-tune (TickRoute) now keys off the SECOND-highest arrival-gap/render-gap
second in the lookback window instead of the single worst, so a lone ~1s
OS/driver stall no longer balloons the buffer to the 200ms cap (the 16:51
trim burst); sustained jitter still reacts at full speed. Logs both gap-max
(true peak) and gap-used (value acted on).

Mic-privacy detector widened: also catches a per-app Deny aimed at this exe
under ConsentStore\microphone\NonPackaged\<exe>, the HKLM NonPackaged gate,
and the Group-Policy/MDM force-deny (AppPrivacy LetAppsAccessMicrophone=2) —
the block shapes that silence WASAPI capture while ASIO sails past, and that
the old three-value check missed.

Forensic instrumentation so the next log proves what happened: capPeak=
(loudest pre-encode sample, per lane, on the diag line), mic-privacy verdict
logged at startup, ui: capture tick/untick events, and device-event: lines for
Windows endpoint changes.

Docs: mic-privacy + auto-tune sections updated in readme.html, MANUAL.md
regenerated, About-box changelog and RELEASE_NOTES for v3.7.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/RemSound.App/RemSound.App.csproj

@@ -14,7 +14,7 @@
          tag_name on the latest GitHub release; bump it on every public release. The
          AssemblyVersion / FileVersion default to this value, and Assembly.GetName().Version
          is what the About dialog and the updater both read. -->
-    <Version>3.6.0</Version>
+    <Version>3.7.0</Version>
   </PropertyGroup>
 
   <ItemGroup>