Implement IMAP email-to-ticket gateway

schema.sql

@@ -0,0 +1,20 @@
+CREATE TABLE IF NOT EXISTS mailgateway_message (
+    message_key CHAR(64) CHARACTER SET ascii COLLATE ascii_bin NOT NULL PRIMARY KEY,
+    mailbox VARCHAR(255) NOT NULL,
+    message_id VARCHAR(998) NOT NULL,
+    payload_hash CHAR(64) CHARACTER SET ascii COLLATE ascii_bin NOT NULL,
+    ticket_id INT DEFAULT NULL,
+    result_json TEXT DEFAULT NULL,
+    created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    INDEX mailgateway_ticket (ticket_id)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+
+CREATE TABLE IF NOT EXISTS mailgateway_notification (
+    sender_key CHAR(64) CHARACTER SET ascii COLLATE ascii_bin NOT NULL PRIMARY KEY,
+    last_notified_at BIGINT NOT NULL
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+
+CREATE TABLE IF NOT EXISTS mailgateway_settings (
+    id SMALLINT NOT NULL PRIMARY KEY,
+    config_encrypted TEXT NOT NULL
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;