Dev release: Maven resolves the pinned timestamped snapshot; the facets guide must not print a count that varies #309

The release of 26.12.1.dev1 failed closed, and nothing was published. Two causes.

The native build resolved the floating 26.12.1-SNAPSHOT from Sonatype, upstream deployed a newer snapshot since the pin was captured (build 28 at 2026-11-07 08:55, the pin is build 26), and the post-build dev_engine_pin.py check saw a different arcadedb-engine jar than the pinned one. A pin that names a timestamped snapshot has to be what Maven resolves, for the engine and for every sibling module.

On the JVM side, one leg (linux/amd64, Python 3.11) of tests/test_docs_facets_page.py printed {'t0/t1': 3} where the page says {'t0/t1': 6} for the TERMS facet of a query over Media whose subtype Photo alone has the COLUMNAR index. I could not reproduce it: 0 of 350 fresh databases here (150 with the native dev0 wheel and 200 with the JVM dev0 wheel) gave anything but source scan and count 6.