Add account version tags to cookies (#5563)

* feat: add user account version to session cookie

Co-authored-by: Copilot <copilot@github.com>

* feat: include user handle in account version hash calculation

* feat: refactor recovery code generation to use a dedicated function

* fix: don't overwrite current session version if updating another user

Co-authored-by: Copilot <copilot@github.com>

* fix: reset session version instead of nullifying the entire session

* fix: short circuit and clear cookie on request invalidation

Co-authored-by: Copilot <copilot@github.com>

* fix: update account version on recovery

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Co-authored-by: Copilot <copilot@github.com>

index.d.ts

@@ -41,6 +41,10 @@ declare global {
              * Authenticated user handle.
              */
             handle: string | null;
+            /**
+             * Account version tag: shake256 derivative of password hash and salt.
+             */
+            version: string | null;
             /**
              * Last time the session was extended.
              */