Release v0.30.4

What's Changed

• feat(app-server): support stateful Responses chaining by @sarahwooders in #3639
• feat(listener): support base64 encoding on read_file device command by @letta-integration[bot] in #3649
• fix(cli): preserve OAuth provider identity in model selector by @overlord-letta in #3651
• feat(whatsapp): add messaging controls and lifecycle hardening by @just-cameron in #3650
• fix(app-server): execute tools without relay connection by @just-cameron in #3654
• chore: bump version to 0.30.4 by @github-actions[bot] in #3652

Full Changelog: v0.30.3...v0.30.4