chore(license): migrate PMPL-1.0-or-later → AGPL-3.0-or-later (Joshua co-dev)

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

@@ -17,7 +17,7 @@ version = "0.2.0"
 description = "PanLL eNSAID - Environment for NeSy-Agentic Integrated Development (Gossamer backend)"
 authors = ["Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>"]
 edition = "2021"
-license = "MPL-2.0"
+license = "AGPL-3.0-or-later"
 repository = "https://github.com/hyperpolymath/panll"
 
 # Testable logic library — GTK/WebKit-free. `cargo test --lib` runs without