[codex] Switch repository license to Apache-2.0

[fabianzimber]

What changed

• replace the repository LICENSE file with the Apache License 2.0 text
• align README license wording and repository badges with the current GitHub org
• bump the package to 0.3.3 for a patch release

Why

The package metadata already declared Apache-2.0, but the checked-in LICENSE file and README still reflected the previous MIT state. This makes the published package metadata and repository licensing consistent.

Validation

• npx -y -p node@24.14.1 -p npm@11.11.0 npm ci
• npx -y -p node@24.14.1 -p npm@11.11.0 npm run lint
• npx -y -p node@24.14.1 -p npm@11.11.0 npm run typecheck
• npx -y -p node@24.14.1 -p npm@11.11.0 npm run test:ci
• npx -y -p node@24.14.1 -p npm@11.11.0 npm run build
• npx -y -p node@24.14.1 -p npm@11.11.0 npm pack --dry-run