chore: license MeshBay — LGPL protocol layer, AGPL for the rest

The protocol layer is LGPL-3.0-or-later in every language it exists in, so
any client may use it whatever its own licence: meshbay-common, and the files
marked with an SPDX line — keyderive.js, crypto.js, playlist-crypto.js,
transport*.js; keyring.js, transcripts.js and argon2-wasm.js on the desktop;
Kdf.kt, Keyring.kt and Transcripts.kt on Android. Everything else is
AGPL-3.0-or-later, which the RPM specs and package.json already declared
without a licence file to back them.

Two AGPL section 7 permissions:
- group applications may be under any licence when they use the interface
  only through a named surface (static/licenses/APPLICATION-EXCEPTION.txt);
  the reference application is 0BSD so that copying it brings no AGPL code;
- the Android application may be conveyed linked with Google Play services.

Third-party code is accounted for: THIRD-PARTY-NOTICES.txt is generated from
what a build ships (packaging/third_party_notices.py) for the deb/rpm venv and
the frozen Windows node — PyAV's wheel grafts in libx264 and libx265, which its
BSD licence does not mention — and the vendored browser libraries get their
licence texts and htm-preact.js its provenance. Wheels carry SPDX metadata,
RPMs %license, debs a DEP-5 copyright file, every Windows target LICENSE.txt.

test_licensing.py holds the line: the LGPL layer imports nothing under the
AGPL, the reference application nothing outside the application interface,
and every SPDX line is one of the known ones.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/packaging/build/build-common.sh b/packaging/build/build-common.sh
index 3045689..5f119c6 100755
--- a/packaging/build/build-common.sh
+++ b/packaging/build/build-common.sh
@@ -44,6 +44,11 @@ echo "    installing all packages + dependencies"
     --find-links "$WHEEL_DIR" \
     meshbay-common meshbay-hub meshbay-node 2>&1 | tail -3
 
+# --- Third-party notices: every package the venv ships, with its licence -------
+echo "    writing THIRD-PARTY-NOTICES.txt"
+"$VENV_BUILD/bin/python" "$REPO/packaging/third_party_notices.py" \
+    -o "$ROOT/opt/meshbay-common/THIRD-PARTY-NOTICES.txt" meshbay-hub meshbay-node
+
 # --- Strip build tools from the venv (not needed at runtime) ---------------
 echo "    stripping build tools"
 "$VENV_BUILD/bin/pip" uninstall -y pip setuptools wheel 2>&1 | tail -1