chore(license): migrate PMPL-1.0-or-later → MPL-2.0 (solo)

Replace LICENSE file with canonical MPL-2.0 text and update package
metadata (Cargo.toml/package.json/deno.json/mix.exs/pyproject.toml where
present) to declare the new SPDX identifier.

Rationale: solo.

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

Author: hyperpolymath

Cargo.toml

@@ -3,7 +3,7 @@ name = "absolute-zero"
 version = "1.0.0"
 edition = "2021"
 description = "Certified Null Operation - A program that does absolutely nothing"
-license = "MIT"
+license = "MPL-2.0"
 
 [profile.release]
 opt-level = "z"