License peo4c under GPL-3.0-or-later and ship third-party notices

- Add the GPL-3.0 LICENSE and SPDX headers to peo4c's own files.
- Add THIRD_PARTY_NOTICES.md listing every bundled component, its
  license and where its license text lives in the image, plus a
  trademark disclaimer; reference it from the README.
- Ship neo4j-browser's LICENSE, NOTICE.txt and LICENSES.txt with a
  source archive of the built commit, as the GPL requires.
- Ship Apache AGE's LICENSE and NOTICE, which the base image lacks.
- Collect license texts for Python packages whose wheels omit them,
  from PyPI sdists or vendored copies in docker/licenses/.

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

Dockerfile

@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2026 Bart Broere
+# SPDX-License-Identifier: GPL-3.0-or-later
+
 # peo4c: neo4j-browser on top of PostgreSQL + Apache AGE.
 #
 # Stage 1 builds the neo4j-browser static frontend from source.
@@ -6,6 +9,8 @@
 # Cypher into AGE `cypher()` calls, and pgAdmin as a SQL interface.
 
 ARG AGE_IMAGE=docker.io/apache/age:release_PG18_1.8.0
+# Commit of apache/age's release/PG18/1.8.0 branch, for AGE's LICENSE and NOTICE.
+ARG AGE_SOURCE_REF=b570cf7c1486863f77c14e9c0e07b0e9bfd01bf4
 ARG PGADMIN_VERSION=9.18
 
 FROM docker.io/library/node:16.20.2-bullseye AS browser
@@ -17,13 +22,15 @@ WORKDIR /src
 RUN git init -q . \
     && git remote add origin "$NEO4J_BROWSER_REPO" \
     && git fetch -q --depth 1 origin "$NEO4J_BROWSER_REF" \
-    && git checkout -q FETCH_HEAD
+    && git checkout -q FETCH_HEAD \
+    && git archive --format=tar.gz --prefix=neo4j-browser/ -o /neo4j-browser-source.tar.gz HEAD
 RUN yarn install --frozen-lockfile --network-timeout 600000
 RUN yarn build && test -f dist/index.html
 
 
 FROM ${AGE_IMAGE}
 
+ARG AGE_SOURCE_REF
 ARG PGADMIN_VERSION
 
 RUN apt-get update \
@@ -37,6 +44,20 @@ RUN python3 -m venv /opt/pgadmin \
     && mkdir -p /var/lib/pgadmin \
     && chown postgres:postgres /var/lib/pgadmin
 
+# License notices: see THIRD_PARTY_NOTICES.md. neo4j-browser is GPL-3.0, so its
+# complete source is shipped next to the license.
+COPY docker/collect-python-licenses.py /tmp/
+COPY docker/licenses/ /tmp/licenses/
+RUN /opt/pgadmin/bin/python /tmp/collect-python-licenses.py \
+        /usr/share/doc/peo4c/pgadmin-python-licenses /tmp/licenses \
+    && rm -r /tmp/collect-python-licenses.py /tmp/licenses
+COPY LICENSE THIRD_PARTY_NOTICES.md /usr/share/doc/peo4c/
+COPY --from=browser /src/LICENSE /src/NOTICE.txt /src/LICENSES.txt /neo4j-browser-source.tar.gz \
+    /usr/share/doc/peo4c/neo4j-browser/
+ADD https://raw.githubusercontent.com/apache/age/${AGE_SOURCE_REF}/LICENSE \
+    https://raw.githubusercontent.com/apache/age/${AGE_SOURCE_REF}/NOTICE \
+    /usr/share/doc/peo4c/apache-age/
+
 COPY --from=browser /src/dist /opt/peo4c/browser
 COPY bridge /opt/peo4c/bridge
 COPY docker/initdb/ /docker-entrypoint-initdb.d/