Rotate the embedded license verification key (1.11.2)

[natiixnt]

What

Rotate the embedded Ed25519 license verification key and bump to 1.11.2.

• _EMBEDDED_PUBLIC_KEY_B64 replaced with the new production public key.
• The previous key is retired; Pro licenses are re-issued under the new key, and licenses signed against the old key no longer verify.
• Verification stays fully offline; the private signer key lives only in redcon-cloud.

Why

The prior signer private key was exposed and is treated as compromised. Rotating the embedded public key ensures licenses are validated against a key whose private half is uncompromised. No user data involved; this is a signing-key rotation.

Verification

• tests/test_entitlements.py overrides the embedded key via monkeypatch, so it is agnostic to the value - suite stays green.
• After release, activation smoke test to be re-run against the 1.11.2 wheel with a license signed by the new key.