Initial commit: email-openclaw bridge v1

Full pipeline: IMAP ingress -> OpenClaw dispatch -> callback -> SMTP reply.
SQLite stateful storage with idempotency, threading, and retry logic.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

internal/database/database.go

@@ -0,0 +1,35 @@
+package database
+
+import (
+	"fmt"
+
+	"github.com/glebarez/sqlite"
+	"gorm.io/gorm"
+	"gorm.io/gorm/logger"
+)
+
+// Open initializes the SQLite database and runs auto-migration.
+func Open(dbPath string) (*gorm.DB, error) {
+	db, err := gorm.Open(sqlite.Open(dbPath), &gorm.Config{
+		Logger: logger.Default.LogMode(logger.Silent), // We use our own structured logger.
+	})
+	if err != nil {
+		return nil, fmt.Errorf("database open: %w", err)
+	}
+
+	// Enable WAL mode for better concurrent read performance.
+	if err := db.Exec("PRAGMA journal_mode=WAL").Error; err != nil {
+		return nil, fmt.Errorf("database pragma WAL: %w", err)
+	}
+
+	if err := db.AutoMigrate(&Task{}); err != nil {
+		return nil, fmt.Errorf("database migrate: %w", err)
+	}
+
+	return db, nil
+}
+
+// Healthy checks if the database is writable.
+func Healthy(db *gorm.DB) error {
+	return db.Exec("SELECT 1").Error
+}