Caddyfile: point the shared family login at dankuser too

The other vhosts (gitea, grafana, search, ...) now use username 'dankuser'
with CADDY_BASICAUTH_HASH, which is set to the same hash as the homepage
(dankpassword.123). So the whole protected surface logs in as
dankuser / dankpassword.123; the operator /admin/ page still uses frank.
Updated the two tests that asserted the old 'dank' username.

tests/caddyfile.bats

@@ -72,7 +72,7 @@ CADDYFILE="$REPO_ROOT/dankclaw/Caddyfile"
         echo "Caddyfile: bcrypt prefix before REPLACE_WITH_HASH (double-prefix regression)"
         return 1
     fi
-    grep -qE 'dank REPLACE_WITH_HASH' "$CADDYFILE"
+    grep -qE 'dankuser REPLACE_WITH_HASH' "$CADDYFILE"
 }
 
 @test "compose no longer defines the quadlet-replaced services" {

tests/deployment_flow.bats

@@ -85,9 +85,9 @@ load helpers
     [ -n "$rendered" ]
     [[ "$rendered" == *"${hash}"* ]]
     ! grep -q 'REPLACE_WITH_HASH' <<< "$rendered"
-    # The rendered line must be exactly "dank <hash>". A template that keeps
-    # its own $2a$14$ prefix renders an invalid double-prefixed hash and
-    # every basicauth vhost returns 401 (2026-08-22 incident).
-    grep -qF "dank ${hash}" <<< "$rendered"
+    # The rendered line must be exactly "dankuser <hash>". A template that
+    # keeps its own $2a$14$ prefix renders an invalid double-prefixed hash
+    # and every basicauth vhost returns 401 (2026-08-22 incident).
+    grep -qF "dankuser ${hash}" <<< "$rendered"
     ! grep -qF '$2a$14$$2a$14$' <<< "$rendered"
 }