KanBorg 1.2.23

Fixes the incomplete application signature that caused macOS to report the downloaded KanBorg app as damaged.

Local macOS packaging now seals the complete bundle with an ad-hoc signature and requires strict signature verification before creating the installer. This remains a local, non-notarized build, not an Apple Developer ID release.

Verified: complete bundle signature, installer checksum, and isolated legacy update/startup test with project restoration and coordinator resume request.