Move sessions to db table instead of JWTs

Sources/stella/Migrations/CreateSessions.swift

@@ -0,0 +1,16 @@
+import Fluent
+
+struct CreateSessions: AsyncMigration {
+    func prepare(on database: any Database) async throws {
+        try await database.schema("sessions")
+            .field("token", .string, .identifier(auto: false))
+            .field("type", .int, .required)
+            .field("expires", .datetime, .required)
+            .field("accountId", .int, .required, .references("accounts", "id"))
+            .create()
+    }
+
+    func revert(on database: any Database) async throws {
+        try await database.schema("sessions").delete()
+    }
+}