chore(license): migrate to AGPL-3.0-or-later (#112)

## Summary
Migrates this repo's license declaration from `MPL-2.0` to
`AGPL-3.0-or-later`.

**Rationale:** Joshua co-dev.

## Changes
- LICENSE file replaced with canonical `AGPL-3.0-or-later` text
(including SPDX header).
- Package metadata updated where present (Cargo.toml, package.json,
deno.json, mix.exs, pyproject.toml).

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

Author: hyperpolymath

Cargo.toml

@@ -5,7 +5,7 @@ name = "echidna"
 version = "2.1.0"
 edition = "2021"
 authors = ["Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>"]
-license = "MPL-2.0"
+license = "AGPL-3.0-or-later"
 description = "Neurosymbolic theorem proving platform with multi-prover support"
 repository = "https://github.com/hyperpolymath/echidna"
 

LICENSE

@@ -7,7 +7,7 @@ edition = "2021"
 description = "Creusot-annotated trust pipeline kernel for ECHIDNA"
 # crates.io requires an OSI-approved identifier; MPL-2.0 is the automatic
 # legal fallback for MPL-2.0 until PMPL achieves formal recognition.
-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/echidna"
 

crates/echidna-core-spark/Cargo.toml

@@ -5,7 +5,7 @@ name = "echidna-core"
 version = "0.1.0"
 edition = "2021"
 authors = ["Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>"]
-license = "MPL-2.0"
+license = "AGPL-3.0-or-later"
 description = "Canonical Term / Goal / ProofState / Tactic types for ECHIDNA, re-used by vcl-ut and any future proof-exchange client without depending on the full echidna binary."
 repository = "https://github.com/hyperpolymath/echidna"
 

crates/echidna-core/Cargo.toml

@@ -5,7 +5,7 @@ name        = "echidna-mcp"
 version     = "0.1.0"
 edition     = "2021"
 authors     = ["Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>"]
-license     = "MPL-2.0"
+license = "AGPL-3.0-or-later"
 description = "Model Context Protocol server exposing ECHIDNA to AI coding agents (Claude Code, Claude API, etc.)"
 repository  = "https://github.com/hyperpolymath/echidna"
 

crates/echidna-mcp/Cargo.toml

@@ -5,7 +5,7 @@ name        = "echidna-wire"
 version     = "0.1.0"
 edition     = "2021"
 authors     = ["Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>"]
-license     = "MPL-2.0"
+license = "AGPL-3.0-or-later"
 description = "L1 IPC wire types for ECHIDNA (Cap'n Proto schemas + generated bindings)"
 repository  = "https://github.com/hyperpolymath/echidna"
 build       = "build.rs"

crates/echidna-wire/Cargo.toml

@@ -5,7 +5,7 @@ name = "typed-wasm"
 version = "0.1.0"
 edition = "2021"
 authors = ["Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>"]
-license = "MPL-2.0"
+license = "AGPL-3.0-or-later"
 description = "TypedWasm prover oracle engine for ECHIDNA — standalone domain types and engine"
 repository = "https://github.com/hyperpolymath/echidna"
 

crates/typed_wasm/Cargo.toml

@@ -3,7 +3,7 @@
   "name": "@echidna/provers",
   "version": "0.1.0",
   "description": "ECHIDNA - Neurosymbolic Theorem Proving Platform",
-  "license": "MPL-2.0",
+  "license": "AGPL-3.0-or-later",
 
   "compilerOptions": {
     "allowJs": false,

deno.json

@@ -2,7 +2,7 @@
   "name": "echidna-ui",
   "version": "0.1.0",
   "description": "ECHIDNA Neurosymbolic Theorem Proving Platform - ReScript UI",
-  "license": "(MIT OR Palimpsest-0.6)",
+  "license": "AGPL-3.0-or-later",
   "type": "module",
   "scripts": {
     "res:build": "rescript build",