docs(standards): finish the sentence the 405 row trails off in

"the `Allow` header lists the methods that are" reads as a truncation. The
content was right — the header is named — but a reader hits the end of the row
looking for the word that never arrives.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: cemililik

docs/standards/04-api-design.md

@@ -62,7 +62,7 @@ shape, and per-deployment-mode behaviour — see ADR-0024 directly.
 | 401 | Missing/invalid authentication |
 | 403 | Authenticated but not authorized |
 | 404 | Not found (also used to hide cross-tenant existence) |
-| 405 | Method not allowed; the `Allow` header lists the methods that are |
+| 405 | Method not allowed; the `Allow` header lists the methods that are permitted |
 | 409 | Concurrency or business-rule conflict |
 | 413 | Request body over the configured limit |
 | 410 | Permanently gone |