fix(server): resolve lack of user isolation

.github/workflows/test-integration.yml

@@ -135,7 +135,7 @@ jobs:
           echo "Running tests with DATABASE_URL: $DATABASE_URL"
           echo "Environment check:"
           env | grep -E "(DATABASE_URL|JWT_SECRET|API_URL)" | sort
-          cargo test --test '*' -- --test-threads=1
+          cargo test --test '*' --features test-utils -- --test-threads=1
         env:
           DATABASE_URL: ${{ env.DATABASE_URL }}
           TEST_DATABASE_URL: ${{ env.DATABASE_URL }}

src/routes/documents.rs

@@ -669,7 +669,7 @@ async fn get_failed_ocr_documents(
             GROUP BY document_id
         ) q ON d.id = q.document_id
         WHERE d.ocr_status = 'failed'
-          AND ($1 = $1 OR d.user_id = $1)  -- Admin can see all, users see only their own
+          AND ($1::uuid IS NULL OR d.user_id = $1)  -- Admin can see all, users see only their own
         ORDER BY d.updated_at DESC
         LIMIT $2 OFFSET $3
         "#