chore: replace em dashes with hyphens, add no-em-dash rule to CLAUDE.md

.gitea/workflows/deploy.yml

@@ -5,7 +5,7 @@ on:
         branches:
             - main
     # DOCS_URL, DOCS_BASE_URL and APP_URL are repo variables, and editing one
-    # pushes no commit — so nothing would rebuild on its own. This is the
+    # pushes no commit - so nothing would rebuild on its own. This is the
     # escape hatch for that, and DOCS_BASE_URL in particular is baked into
     # every asset path in the build.
     workflow_dispatch:
@@ -27,7 +27,7 @@ jobs:
                     docker login ${{ vars.DOCKER_HOST }} \
                       -u "${{ secrets.REGISTRY_USER }}" --password-stdin
 
-            # One image, one directory — the whole repository is the docs site,
+            # One image, one directory - the whole repository is the docs site,
             # so there is nothing to detect a change in. It rebuilds on every
             # push, which is what a docs site wants anyway.
             #