fix(spore): fix Log Explorer host variable allValue matcher (#394)

Loki rejects `{host=~".*"}` because `.*` matches empty strings.
Change allValue from `.*` to `.+` so the "All" selection produces
a valid stream selector.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: stackptr

hosts/spore/services/dashboards/logs.json

@@ -183,7 +183,7 @@
         "current": { "selected": true, "text": "All", "value": "$__all" },
         "hide": 0,
         "includeAll": true,
-        "allValue": ".*",
+        "allValue": ".+",
         "label": "Host",
         "multi": true,
         "name": "host",