Migrate module path from kyle/ to mc/ org

All import paths updated to git.wntrmute.dev/mc/. Bumps mcdsl to v1.2.0.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/engineering-standards.md

@@ -138,7 +138,7 @@ but the top-level skeleton is fixed.
 Services hosted on `git.wntrmute.dev` use:
 
 ```
-git.wntrmute.dev/kyle/<service>
+git.wntrmute.dev/mc/<service>
 ```
 
 ---
@@ -251,7 +251,7 @@ Access Service). No service maintains its own user database.
 
 - Client sends credentials to the service's `/v1/auth/login` endpoint.
 - The service forwards them to MCIAS via the client library
-  (`git.wntrmute.dev/kyle/mcias/clients/go`).
+  (`git.wntrmute.dev/mc/mcias/clients/go`).
 - On success, MCIAS returns a bearer token. The service returns it to the
   client and optionally sets it as a cookie for the web UI.
 - Subsequent requests include the token via `Authorization: Bearer <token>`