docs: tidy manual test checklist

Clarify that the manual scenarios remain useful for real browser and deployment
retests, and keep the nginx deployment retest item separate from the checksum
command example.

Test Plan:
- just check

TESTS.md

@@ -29,8 +29,8 @@ Keep this file as the reusable verification checklist while implementing
 
 ## Manual
 
-These scenarios come from `PLAN.md` and should be retested as the matching
-features land.
+These scenarios come from `PLAN.md` and remain useful for real browser and
+deployment retests.
 
 - Upload a small file in one pass.
 - Upload a file larger than one chunk.
@@ -46,10 +46,10 @@ features land.
 - Retry a duplicate chunk and confirm it is accepted idempotently.
 - Attempt an invalid chunk index and confirm it is rejected.
 - Attempt a wrong-size non-final chunk and confirm it is rejected.
-- Complete an upload and compare the final file with the source file:
 - Install `deploy/nginx/upl.conf.example` on the deployment host, add the real
   TLS certificate and access-control settings, and repeat the resume scenarios
   through the public nginx URL.
+- Complete an upload and compare the final file with the source file:
 
 ```sh
 sha256sum source-file data/complete/uploaded-file