feat: add spacetimedb json migration tooling

scripts/spacetime-import-migration-json.mjs

@@ -0,0 +1,60 @@
+#!/usr/bin/env node
+
+import { readFile } from 'node:fs/promises';
+import path from 'node:path';
+import {
+  assertReadableFile,
+  callSpacetimeProcedureAuto,
+  ensureProcedureOk,
+  parseArgs,
+} from './spacetime-migration-common.mjs';
+
+try {
+  const options = parseArgs(process.argv.slice(2));
+  if (!options.in) {
+    throw new Error('必须传入 --in。');
+  }
+
+  const inPath = path.resolve(options.in);
+  await assertReadableFile(inPath);
+  const migrationJson = await readFile(inPath, 'utf8');
+  if (!migrationJson.trim()) {
+    throw new Error(`迁移文件为空: ${inPath}`);
+  }
+
+  const input = {
+    migration_json: migrationJson,
+    include_tables: options.includeTables,
+    replace_existing: options.replaceExisting === true,
+    dry_run: options.dryRun === true,
+  };
+  const result = await callSpacetimeProcedureAuto(
+    options,
+    'import_database_migration_from_file',
+    input,
+  );
+  ensureProcedureOk(result);
+
+  console.log(
+    `[spacetime:migration:import] ${options.dryRun ? 'dry-run 完成' : '导入完成'}: ${inPath}`,
+  );
+  printTableStats(result.table_stats);
+} catch (error) {
+  console.error(
+    `[spacetime:migration:import] ${error instanceof Error ? error.message : String(error)}`,
+  );
+  process.exit(1);
+}
+
+function printTableStats(tableStats) {
+  if (!Array.isArray(tableStats) || tableStats.length === 0) {
+    return;
+  }
+
+  const rows = tableStats.map((stat) => ({
+    table: stat.table_name,
+    imported: stat.imported_row_count,
+    skipped: stat.skipped_row_count,
+  }));
+  console.table(rows);
+}