Free Sound Recorder 8.1.0: complete source distribution

Start with Source/README-BUILD.txt and Source/BUILD-FORMAL.ps1. Build into a new
RebuiltApplication directory; never overwrite a released signed application.
The .NET SDK and package versions are pinned. Source includes the full exact
AudioMass editor and readable lamejs derivative; license and modification
instructions are in Source/Licenses. Installer includes only public resources,
Microsoft's signed WebView2 bootstrapper, and the approved optional RK flow.
No signing certificate, token, account password, or private key is included.

The regression tests use synthetic PCM and recorder state only, never real audio
devices. Run from QA/RecorderStateTests: dotnet run -c Release -- <new-QA-output>
Run mix checks: node QA/multitrack-mix-tests.cjs
The native test checks its temporary path containment before invoking Cancel.
Only run test builds in your own working directory, not an installed app folder.

Archive MANIFEST.json lists every supplied source file and SHA-256 checksum.

English-label revision: only editable www/ presentation assets change. The signed native host is unchanged. Device IDs and recording data are not renamed. New synthetic display-label tests are included under QA.
