feat: convert file manager into a plugin

drizzle/mysql/0036_dear_vapor.sql

@@ -0,0 +1,5 @@
+-- file_manager_pinned, file_manager_recent, file_manager_shortcuts and
+-- transfer_recent are adopted (renamed, not dropped) by the file-manager
+-- plugin's own migration, which runs at plugin activation, after core's
+-- drizzle migrations. A DROP TABLE here would run first and delete the data.
+SELECT 1;

drizzle/mysql/meta/_journal.json

@@ -253,6 +253,13 @@
       "when": 1790185584715,
       "tag": "0035_clumsy_leech",
       "breakpoints": true
+    },
+    {
+      "idx": 36,
+      "version": "5",
+      "when": 1790189637531,
+      "tag": "0036_dear_vapor",
+      "breakpoints": true
     }
   ]
 }