chore: relicense from MIT to Apache-2.0

Replace the MIT LICENSE with the full Apache License 2.0 text, update the
SPDX license field in package.json and package-lock.json, and adapt the
README badge and License section accordingly.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

package.json

@@ -2,7 +2,7 @@
   "name": "@mobiletic-labs/anonymizer",
   "version": "0.4.0",
   "description": "Framework-agnostic PII anonymization & pseudonymization: pluggable LLM detection for free-form PII (names, addresses) with a deterministic regex fallback, deterministic coreference, and streaming-safe de-anonymization.",
-  "license": "MIT",
+  "license": "Apache-2.0",
   "author": "Mobiletic",
   "homepage": "https://git.mobiletic.net/mobiletic-labs/anonymizer#readme",
   "repository": {