fix: add missing created_by column to archer_tickets table

backend/db-schema.sql

@@ -145,6 +145,7 @@ CREATE TABLE IF NOT EXISTS archer_tickets (
     status TEXT DEFAULT 'Draft' CHECK (status IN ('Draft', 'Open', 'Under Review', 'Accepted')),
     cve_id TEXT NOT NULL,
     vendor TEXT NOT NULL,
+    created_by INTEGER REFERENCES users(id),
     created_at TIMESTAMPTZ DEFAULT NOW(),
     updated_at TIMESTAMPTZ DEFAULT NOW()
 );