wip: replace ndk cache with metadata table

src-tauri/migrations/20230921085234_add_metadata_table.sql

@@ -0,0 +1,9 @@
+-- Add migration script here
+CREATE TABLE
+  metadata (
+    id TEXT NOT NULL PRIMARY KEY,
+    event TEXT NOT NULL,
+    author TEXT NOT NULL,
+    kind NUMBER NOT NULL DEFAULt 0,
+    created_at INTEGER NOT NULL
+  );