feat(migrations): add last_active_at column to users table

src/backend/migrations/005-add-user-lastactiveat.sql

@@ -0,0 +1,24 @@
+-- ## Migration add some extra fields.
+-- * Add last_active_at to users.
+
+-- Related issues:
+-- https://github.com/hotosm/fmtm/issues/1999
+
+-- Start a transaction
+
+BEGIN;
+
+DO $$
+BEGIN
+    IF NOT EXISTS (
+        SELECT 1
+        FROM information_schema.columns
+        WHERE table_name = 'users'
+          AND column_name = 'last_active_at'
+    ) THEN
+        ALTER TABLE users ADD COLUMN last_active_at TIMESTAMPTZ DEFAULT now();
+    END IF;
+END $$;
+
+-- Commit the transaction
+COMMIT;

src/backend/migrations/revert/005-add-user-lastactiveat.sql

@@ -0,0 +1,16 @@
+-- Start a transaction
+
+DO $$
+BEGIN
+    IF EXISTS (
+        SELECT 1
+        FROM information_schema.columns
+        WHERE table_name = 'users'
+          AND column_name = 'last_active_at'
+    ) THEN
+        ALTER TABLE users DROP COLUMN last_active_at;
+    END IF;
+END $$;
+
+-- Commit the transaction
+COMMIT;