Initial commit: TutaBridge IMAP/SMTP bridge for Tuta

Local bridge that exposes Tuta encrypted email via standard
IMAP/SMTP protocols for use with Thunderbird and other clients.

Features:
- IMAP server with TLS (STARTTLS self-signed cert)
- SMTP server for sending mail via Tuta
- Session persistence via macOS Keychain
- Mail body decryption including LZ4-compressed blobs
- Blob storage access (BlobAccessTokenService + blob server)
- RFC 2822 message formatting
- Interactive first-run configuration

.gitignore

@@ -0,0 +1,2 @@
+/target
+/tuta-repo