chore(license): migrate MPL-2.0 → AGPL-3.0-or-later (Joshua co-dev) (#40)

Replace LICENSE file with canonical AGPL-3.0-or-later text and update package
metadata (Cargo.toml/package.json/deno.json/mix.exs/pyproject.toml where
present) to declare the new SPDX identifier.

Rationale: Joshua co-dev.

Part of estate-wide metadata cleanup 2026-05-26.

Author: hyperpolymath

Cargo.toml

@@ -3,7 +3,7 @@
 name = "vcl-total"
 version = "0.1.0"
 edition = "2021"
-license = "MPL-2.0"
+license = "AGPL-3.0-or-later"
 authors = ["Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>"]
 repository = "https://github.com/hyperpolymath/vql-ut"
 description = "VCL-total: 10-level type-safe query language for VeriSimDB"