feat: folder shares apply to hosts added later (#1343)

* feat: folder shares apply to hosts added later

Sharing a folder only fanned grants out to the hosts in it at the time.
The share is now also kept as a standing rule on the folder, and a host
created in or moved into it (or a subfolder) inherits the same access
and secret snapshots. Rules follow folder renames and can be stopped
from the share dialog.

* fix: stabilize folder access migrations

drizzle/mysql/meta/_journal.json

@@ -134,6 +134,13 @@
       "when": 1787600445146,
       "tag": "0018_fancy_barracuda",
       "breakpoints": true
+    },
+    {
+      "idx": 19,
+      "version": "5",
+      "when": 1787602480861,
+      "tag": "0019_certain_archangel",
+      "breakpoints": true
     }
   ]
 }