add files meta data

backend/internal/db/migrations/schema.sql

@@ -1,4 +1,20 @@
--- VaultDrop Schema
--- Tables will be added here as the project evolves.
+CREATE TABLE files (
+  id TEXT PRIMARY KEY,
+  name TEXT NOT NULL,
+  storage_key TEXT NOT NULL,
+  checksum TEXT,
+  created_at INTEGER NOT NULL,
+  updated_at INTEGER NOT NULL,
+  deleted_at INTEGER
+);
 
-SELECT 1;
+CREATE TABLE tags (
+  id TEXT PRIMARY KEY,
+  name TEXT NOT NULL
+);
+
+CREATE TABLE file_tags (
+  file_id TEXT NOT NULL,
+  tag_id TEXT NOT NULL,
+  PRIMARY KEY (file_id, tag_id)
+);