feat: convert file manager into a plugin

drizzle/sqlite/0033_careful_random.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/sqlite/meta/_journal.json

@@ -232,6 +232,13 @@
       "when": 1790185583660,
       "tag": "0032_square_jack_power",
       "breakpoints": true
+    },
+    {
+      "idx": 33,
+      "version": "6",
+      "when": 1790189636471,
+      "tag": "0033_careful_random",
+      "breakpoints": true
     }
   ]
 }