chore(license): migrate to MPL-2.0 (#49)

## Summary
Migrates this repo's license declaration from `PMPL-1.0-or-later` to
`MPL-2.0`.

**Rationale:** solo.

## Changes
- LICENSE file replaced with canonical `MPL-2.0` 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

@@ -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"