feat: implement auto-run migrations for medications table to handle image_url column

backend/src/db/client.ts

@@ -8,3 +8,25 @@ const url = process.env.DATABASE_URL || "file:./data/medassist.db";
 const client = createClient({ url });
 
 export const db = drizzle(client);
+
+// Auto-run migrations on import (self-healing database)
+async function runMigrations() {
+  const migrations = [
+    { name: "image_url", sql: "ALTER TABLE medications ADD COLUMN image_url TEXT" },
+  ];
+
+  for (const migration of migrations) {
+    try {
+      await client.execute(migration.sql);
+      console.log(`[DB] Migration applied: ${migration.name}`);
+    } catch (e: any) {
+      // Ignore "duplicate column" errors - column already exists
+      if (!e.message?.includes("duplicate column")) {
+        console.error(`[DB] Migration error (${migration.name}):`, e.message);
+      }
+    }
+  }
+}
+
+// Run migrations immediately
+runMigrations().catch(console.error);