Port bun-mariadb conventions: init globals, db handler, split schema sync

- init() loads config, schema and the SQLite client once into globals
- all CRUD queries go through lib/db-handler.ts (optional per-call config)
- split db-schema-manager.ts into lib/schema/* with FK-aware table ordering
- add bun:test tests for schema ordering, FK constraints and schema sync
- config/schema files can be .ts/.js/.json/.yaml/.yml; db_schema_file_name
  is now optional (defaults to schema.* in db_dir)
- add export/import commands (database snapshot + schema archives)
- package exports map, type re-exports, hardened publish.sh
- validate table name in delete

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/commands/backup.ts

@@ -1,11 +1,9 @@
 import { Command } from "commander";
-import init from "../functions/init";
 import path from "path";
 import grabDBDir from "../utils/grab-db-dir";
 import grabDBBackupFileName from "../utils/grab-db-backup-file-name";
 import chalk from "chalk";
 import trimBackups from "../utils/trim-backups";
-import DbClient from "../lib/sqlite";
 import snapshotDb from "../utils/snapshot-db";
 
 export default function () {
@@ -14,14 +12,14 @@ export default function () {
         .action(async (opts) => {
             console.log(`Backing up database ...`);
 
-            const { config } = await init();
+            const config = global.CONFIG;
 
             const { backup_dir } = grabDBDir({ config });
 
             const new_db_file_name = grabDBBackupFileName({ config });
 
             snapshotDb({
-                db: DbClient,
+                db: global.SQLITE_CLIENT,
                 dst: path.join(backup_dir, new_db_file_name),
             });