feat: move snippets backend and tables into a plugin (B2)

drizzle/postgres/0034_free_smiling_tiger.sql

@@ -0,0 +1,4 @@
+-- snippets, snippet_folders and snippet_access moved to the snippets plugin
+-- (p_snippets_*), adopted by rename rather than dropped. A real DROP TABLE
+-- here would run before the plugin's adoption migration and delete every row.
+SELECT 1;

drizzle/postgres/meta/_journal.json

@@ -239,6 +239,13 @@
       "when": 1790166644445,
       "tag": "0033_bent_trish_tilby",
       "breakpoints": true
+    },
+    {
+      "idx": 34,
+      "version": "7",
+      "when": 1790169398038,
+      "tag": "0034_free_smiling_tiger",
+      "breakpoints": true
     }
   ]
 }