feat(storage): mosaic storage migrate-tier with dry-run + idempotency (FED-M1-05) (#474)

packages/storage/src/migrate-tier.ts

@@ -0,0 +1,697 @@
+/**
+ * migrate-tier.ts — Core logic for `mosaic storage migrate-tier`.
+ *
+ * Migrates data from `tier: local` (PGlite, normalized Drizzle schema) or
+ * `tier: standalone` (Postgres without pgvector) → `tier: federated`
+ * (Postgres + pgvector).
+ *
+ * Source: DrizzleMigrationSource — reads from the NORMALIZED Drizzle/relational
+ *   schema tables (not the flat `id TEXT + data JSONB` PgliteAdapter schema).
+ *   Both local (PGlite) and standalone (Postgres) sources use the same Drizzle
+ *   abstraction via createPgliteDb() or createDb() from @mosaicstack/db.
+ * Target: PostgresMigrationTarget — upserts via raw SQL into the same schema.
+ *
+ * Key design decisions:
+ * - Tables are migrated in topological (FK-dependency) order so that
+ *   parent rows exist before child rows are inserted.
+ * - sessions + verifications are skipped — they are ephemeral / TTL'd.
+ * - adminTokens is skipped — token hashes are environment-specific
+ *   and should be re-issued on the target.
+ * - insights.embedding is omitted from source SELECT when the source lacks
+ *   pgvector (local/PGlite tier); target insert gets NULL for that column.
+ *   insights.embedding is nullable per schema (no .notNull() constraint).
+ * - Each table's batch is wrapped in a transaction for atomicity.
+ * - Upsert semantics (ON CONFLICT DO UPDATE) make re-runs idempotent.
+ *
+ * TODO (FED-M1-08): Add integration tests against real PGlite → real PG.
+ */
+
+import postgres from 'postgres';
+import * as schema from '@mosaicstack/db';
+import { sql as drizzleSql } from '@mosaicstack/db';
+
+/* ------------------------------------------------------------------ */
+/*  Types                                                               */
+/* ------------------------------------------------------------------ */
+
+export interface MigrationSource {
+  /**
+   * Return all rows from a table (normalized Drizzle schema rows).
+   * When sourceHasVector is false and the table has a vector column,
+   * the source MUST omit the vector column from the result and the
+   * caller will set it to null (see normaliseSourceRow).
+   */
+  readTable(
+    tableName: string,
+    opts?: { limit?: number; offset?: number },
+  ): Promise<Record<string, unknown>[]>;
+
+  /** Count rows in a table. */
+  count(tableName: string): Promise<number>;
+
+  /** Close the source connection. */
+  close(): Promise<void>;
+}
+
+export interface MigrationTarget {
+  /**
+   * Upsert a batch of rows into a table.
+   * Must use ON CONFLICT (id) DO UPDATE semantics.
+   */
+  upsertBatch(tableName: string, rows: Record<string, unknown>[]): Promise<void>;
+
+  /**
+   * Count rows in a target table.
+   */
+  count(tableName: string): Promise<number>;
+
+  /**
+   * Check whether pgvector extension is installed.
+   */
+  hasPgvector(): Promise<boolean>;
+
+  /** Close the target connection. */
+  close(): Promise<void>;
+}
+
+export interface MigrateTierOptions {
+  /** Target postgres connection URL. */
+  targetUrl: string;
+  /** Whether to skip all writes (dry-run). */
+  dryRun: boolean;
+  /** Skip the non-empty target guard. */
+  allowNonEmpty: boolean;
+  /** Rows per transaction batch. */
+  batchSize: number;
+  /** Called with progress messages. */
+  onProgress: (msg: string) => void;
+}
+
+export interface TableMigrationResult {
+  table: string;
+  rowsMigrated: number;
+  skipped: boolean;
+  skipReason?: string;
+}
+
+export interface MigrateTierResult {
+  tables: TableMigrationResult[];
+  totalRows: number;
+  dryRun: boolean;
+}
+
+/* ------------------------------------------------------------------ */
+/*  Schema: FK-aware topological table order                           */
+/* ------------------------------------------------------------------ */
+
+/**
+ * SKIP_TABLES: ephemeral or environment-specific tables not worth migrating.
+ *
+ * - sessions: TTL'd auth sessions — invalid in new environment.
+ * - verifications: one-time tokens (email verify, etc.) — already expired.
+ * - admin_tokens: hashed tokens bound to old environment keys — re-issue.
+ */
+export const SKIP_TABLES = new Set(['sessions', 'verifications', 'admin_tokens']);
+
+/**
+ * Topologically ordered table list (parents before children).
+ *
+ * Derived from FK references in packages/db/src/schema.ts:
+ *
+ *   users                 (no FKs)
+ *   teams                 → users
+ *   team_members          → teams, users
+ *   accounts              → users
+ *   projects              → users, teams
+ *   agents                → projects, users
+ *   missions              → projects, users
+ *   tasks                 → projects, missions
+ *   mission_tasks         → missions, tasks, users
+ *   conversations         → users, projects, agents
+ *   messages              → conversations
+ *   preferences           → users
+ *   insights              → users  [has embedding vector column]
+ *   agent_logs            → users
+ *   skills                → users (installedBy, nullable)
+ *   routing_rules         → users (userId, nullable)
+ *   provider_credentials  → users
+ *   appreciations         (no FKs)
+ *   events                (no FKs)
+ *   tickets               (no FKs)
+ *   summarization_jobs    (no FKs)
+ *
+ * Skipped (not in this list):
+ *   sessions              → users  (ephemeral)
+ *   verifications         (no FKs, ephemeral)
+ *   admin_tokens          → users  (environment-specific)
+ */
+export const MIGRATION_ORDER: string[] = [
+  'users',
+  'teams',
+  'team_members',
+  'accounts',
+  'projects',
+  'agents',
+  'missions',
+  'tasks',
+  'mission_tasks',
+  'conversations',
+  'messages',
+  'preferences',
+  'insights',
+  'agent_logs',
+  'skills',
+  'routing_rules',
+  'provider_credentials',
+  'appreciations',
+  'events',
+  'tickets',
+  'summarization_jobs',
+];
+
+/** Tables that carry a vector embedding column on the target. */
+const VECTOR_TABLES = new Set(['insights']);
+
+/* ------------------------------------------------------------------ */
+/*  Utility: derive topological order from an adjacency list           */
+/* ------------------------------------------------------------------ */
+
+/**
+ * Given an adjacency list (table → list of tables it depends on),
+ * return a valid topological ordering (Kahn's algorithm).
+ *
+ * Exposed for unit testing.
+ */
+export function topoSort(deps: Map<string, string[]>): string[] {
+  const nodes = [...deps.keys()];
+  const inDegree = new Map<string, number>();
+  const adjReverse = new Map<string, string[]>();
+
+  for (const node of nodes) {
+    if (!inDegree.has(node)) inDegree.set(node, 0);
+    if (!adjReverse.has(node)) adjReverse.set(node, []);
+    for (const dep of deps.get(node) ?? []) {
+      inDegree.set(node, (inDegree.get(node) ?? 0) + 1);
+      if (!adjReverse.has(dep)) adjReverse.set(dep, []);
+      adjReverse.get(dep)!.push(node);
+    }
+  }
+
+  // Start with nodes that have no dependencies.
+  const queue: string[] = [];
+  for (const [node, deg] of inDegree) {
+    if (deg === 0) queue.push(node);
+  }
+
+  const result: string[] = [];
+  while (queue.length > 0) {
+    const node = queue.shift()!;
+    result.push(node);
+    for (const dependent of adjReverse.get(node) ?? []) {
+      const newDeg = (inDegree.get(dependent) ?? 0) - 1;
+      inDegree.set(dependent, newDeg);
+      if (newDeg === 0) queue.push(dependent);
+    }
+  }
+
+  if (result.length !== nodes.length) {
+    throw new Error('Cycle detected in FK dependency graph');
+  }
+  return result;
+}
+
+/**
+ * Return the migration table order, excluding SKIP_TABLES.
+ * Uses the pre-computed MIGRATION_ORDER (verified against schema.ts).
+ */
+export function getMigrationOrder(): string[] {
+  return MIGRATION_ORDER.filter((t) => !SKIP_TABLES.has(t));
+}
+
+/* ------------------------------------------------------------------ */
+/*  TABLE_OBJECTS: migration table name → Drizzle table object         */
+/* ------------------------------------------------------------------ */
+
+/**
+ * Maps MIGRATION_ORDER table names to their corresponding Drizzle table
+ * objects from the normalized schema.  Used by DrizzleMigrationSource to
+ * execute typed `db.select().from(table)` queries.
+ *
+ * Keyed by snake_case table name (matching MIGRATION_ORDER + SKIP_TABLES).
+ */
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+const TABLE_OBJECTS: Record<string, any> = {
+  users: schema.users,
+  teams: schema.teams,
+  team_members: schema.teamMembers,
+  accounts: schema.accounts,
+  projects: schema.projects,
+  agents: schema.agents,
+  missions: schema.missions,
+  tasks: schema.tasks,
+  mission_tasks: schema.missionTasks,
+  conversations: schema.conversations,
+  messages: schema.messages,
+  preferences: schema.preferences,
+  insights: schema.insights,
+  agent_logs: schema.agentLogs,
+  skills: schema.skills,
+  routing_rules: schema.routingRules,
+  provider_credentials: schema.providerCredentials,
+  appreciations: schema.appreciations,
+  events: schema.events,
+  tickets: schema.tickets,
+  summarization_jobs: schema.summarizationJobs,
+  // Skipped tables — included so count() works for preflight but never passed
+  // to upsertBatch.
+  sessions: schema.sessions,
+  verifications: schema.verifications,
+  admin_tokens: schema.adminTokens,
+};
+
+/* ------------------------------------------------------------------ */
+/*  DrizzleMigrationSource                                              */
+/* ------------------------------------------------------------------ */
+
+/**
+ * MigrationSource backed by a Drizzle DB handle (works with both
+ * PostgresJsDatabase and PgliteDatabase — they share the same Drizzle
+ * query API for schema-defined tables).
+ *
+ * For the `insights` table (the only vector-column table), when the source
+ * lacks pgvector (local/PGlite tier), the `embedding` column is excluded
+ * from the SELECT projection via a raw `db.execute()` query that lists
+ * only non-vector columns.  This prevents a type-registration error from
+ * PGlite, which does not know the `vector` type.  The caller (runMigrateTier
+ * via normaliseSourceRow) will set embedding to null on the resulting rows.
+ *
+ * Column projection is opt-in: pass `sourceHasVector: false` to activate it.
+ */
+export class DrizzleMigrationSource implements MigrationSource {
+  constructor(
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    private readonly db: any,
+    private readonly sourceHasVector: boolean = true,
+  ) {}
+
+  /**
+   * Columns of the insights table that do NOT include the vector embedding.
+   * Used for the no-pgvector projection path.
+   */
+  private static readonly INSIGHTS_COLUMNS_NO_VECTOR = [
+    'id',
+    'user_id',
+    'content',
+    'source',
+    'category',
+    'relevance_score',
+    'metadata',
+    'created_at',
+    'updated_at',
+    'decayed_at',
+  ] as const;
+
+  async readTable(
+    tableName: string,
+    opts?: { limit?: number; offset?: number },
+  ): Promise<Record<string, unknown>[]> {
+    const table = TABLE_OBJECTS[tableName];
+    if (!table) throw new Error(`DrizzleMigrationSource: unknown table "${tableName}"`);
+
+    // For vector tables when source lacks pgvector: use column-allowlist raw query
+    // to avoid type-registration errors.
+    if (VECTOR_TABLES.has(tableName) && !this.sourceHasVector) {
+      const cols = DrizzleMigrationSource.INSIGHTS_COLUMNS_NO_VECTOR.map((c) => `"${c}"`).join(
+        ', ',
+      );
+      let sql = `SELECT ${cols} FROM "${tableName}"`;
+      const params: unknown[] = [];
+      if (opts?.limit !== undefined) {
+        params.push(opts.limit);
+        sql += ` LIMIT $${params.length.toString()}`;
+      }
+      if (opts?.offset !== undefined) {
+        params.push(opts.offset);
+        sql += ` OFFSET $${params.length.toString()}`;
+      }
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      const result = await (this.db as any).execute(
+        // drizzle-orm/pglite and drizzle-orm/postgres-js both accept a raw
+        // SQL template; use the tagged-template sql helper from drizzle-orm.
+        // Since we need dynamic params, we use db.execute with a raw string
+        // via the PGlite/postgres.js driver directly.
+        { sql, params, typings: [] },
+      );
+      // drizzle execute returns { rows: unknown[][] } for PGlite driver,
+      // or a RowList for postgres.js. Normalise both shapes.
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      const raw = result as any;
+      if (Array.isArray(raw)) {
+        // postgres.js shape: array of row objects
+        return raw as Record<string, unknown>[];
+      }
+      if (raw?.rows && Array.isArray(raw.rows)) {
+        // PGlite shape: { rows: unknown[][] } OR { rows: Record<string,unknown>[] }
+        const rows = raw.rows as unknown[];
+        if (rows.length === 0) return [];
+        if (Array.isArray(rows[0])) {
+          // Columnar: convert to objects using fields array if available
+          const fields: string[] =
+            (raw.fields as Array<{ name: string }> | undefined)?.map((f) => f.name) ??
+            DrizzleMigrationSource.INSIGHTS_COLUMNS_NO_VECTOR.slice();
+          return (rows as unknown[][]).map((row) => {
+            const obj: Record<string, unknown> = {};
+            for (let i = 0; i < fields.length; i++) {
+              obj[fields[i]!] = row[i];
+            }
+            return obj;
+          });
+        }
+        return rows as Record<string, unknown>[];
+      }
+      return [];
+    }
+
+    // Standard Drizzle select for all other tables (and vector tables when
+    // the source has pgvector registered).
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    let query = (this.db as any).select().from(table);
+    if (opts?.limit !== undefined) query = query.limit(opts.limit);
+    if (opts?.offset !== undefined) query = query.offset(opts.offset);
+    return (await query) as Record<string, unknown>[];
+  }
+
+  async count(tableName: string): Promise<number> {
+    const table = TABLE_OBJECTS[tableName];
+    if (!table) throw new Error(`DrizzleMigrationSource: unknown table "${tableName}"`);
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const [row] = await (this.db as any)
+      .select({ n: drizzleSql<number>`COUNT(*)::int` })
+      .from(table);
+    return (row as { n: number } | undefined)?.n ?? 0;
+  }
+
+  async close(): Promise<void> {
+    // Lifecycle managed externally — caller closes the db handle.
+  }
+}
+
+/* ------------------------------------------------------------------ */
+/*  Real postgres target adapter                                        */
+/* ------------------------------------------------------------------ */
+
+/**
+ * Live implementation of MigrationTarget backed by a real Postgres connection.
+ * Used by the CLI; mocked in tests.
+ */
+export class PostgresMigrationTarget implements MigrationTarget {
+  private sql: ReturnType<typeof postgres>;
+
+  constructor(url: string) {
+    this.sql = postgres(url, {
+      max: 5,
+      connect_timeout: 10,
+      idle_timeout: 30,
+    });
+  }
+
+  async upsertBatch(tableName: string, rows: Record<string, unknown>[]): Promise<void> {
+    if (rows.length === 0) return;
+
+    // Collect all column names from the batch (union of all row keys).
+    const colSet = new Set<string>();
+    for (const row of rows) {
+      for (const k of Object.keys(row)) colSet.add(k);
+    }
+    const cols = [...colSet];
+    if (!cols.includes('id')) {
+      throw new Error(`Table ${tableName}: rows missing 'id' column`);
+    }
+
+    // Build VALUES list — use postgres tagged-template helpers for safety.
+    // postgres.js supports bulk inserts via array of objects.
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    await this.sql.begin(async (tx: any) => {
+      // Insert in chunks to avoid enormous single queries.
+      for (let i = 0; i < rows.length; i += 500) {
+        const chunk = rows.slice(i, i + 500);
+
+        // Normalise rows: fill missing columns with null.
+        const normalised = chunk.map((row) => {
+          const out: Record<string, unknown> = {};
+          for (const col of cols) {
+            out[col] = row[col] ?? null;
+          }
+          return out;
+        });
+
+        const colList = cols.map((c) => `"${c}"`).join(', ');
+        const updateList = cols
+          .filter((c) => c !== 'id')
+          .map((c) => `"${c}" = EXCLUDED."${c}"`)
+          .join(', ');
+
+        // Build values placeholders
+        const valuePlaceholders = normalised
+          .map((_, ri) => `(${cols.map((_, ci) => `$${ri * cols.length + ci + 1}`).join(', ')})`)
+          .join(', ');
+
+        const flatValues = normalised.flatMap((row) => cols.map((c) => row[c] ?? null));
+
+        const query = `
+          INSERT INTO "${tableName}" (${colList})
+          VALUES ${valuePlaceholders}
+          ON CONFLICT (id) DO UPDATE SET ${updateList}
+        `;
+
+        await tx.unsafe(query, flatValues as never[]);
+      }
+    });
+  }
+
+  async count(tableName: string): Promise<number> {
+    const rows = await this.sql.unsafe(`SELECT COUNT(*)::int AS n FROM "${tableName}"`);
+    const row = rows[0] as unknown as { n: number } | undefined;
+    return row?.n ?? 0;
+  }
+
+  async hasPgvector(): Promise<boolean> {
+    const rows = await this.sql`
+      SELECT 1 FROM pg_extension WHERE extname = 'vector'
+    `;
+    return rows.length > 0;
+  }
+
+  async close(): Promise<void> {
+    await this.sql.end();
+  }
+}
+
+/* ------------------------------------------------------------------ */
+/*  Source-row normalisation                                           */
+/* ------------------------------------------------------------------ */
+
+/**
+ * Drizzle returns rows as camelCase TypeScript objects (e.g. `userId`, not
+ * `user_id`). The PostgresMigrationTarget upserts via raw SQL and uses the
+ * column names as given — the `insights` no-vector path uses snake_case column
+ * aliases in the SELECT, so those rows already arrive as snake_case.
+ *
+ * For vector tables (insights), if `embedding` is absent from the source row
+ * (because DrizzleMigrationSource omitted it in the no-vector projection), we
+ * explicitly set it to null so the target ON CONFLICT UPDATE doesn't error.
+ *
+ * NOTE: insights.embedding is defined as `vector('embedding', { dimensions:
+ * 1536 })` with no `.notNull()` in schema.ts — it accepts NULL.
+ */
+export function normaliseSourceRow(
+  tableName: string,
+  row: Record<string, unknown>,
+  sourceHasVector: boolean,
+): Record<string, unknown> {
+  const out = { ...row };
+
+  if (VECTOR_TABLES.has(tableName) && !sourceHasVector) {
+    // Source cannot have embeddings — explicitly null them so ON CONFLICT
+    // UPDATE doesn't try to write undefined.
+    out['embedding'] = null;
+  }
+
+  return out;
+}
+
+/* ------------------------------------------------------------------ */
+/*  Precondition checks                                                 */
+/* ------------------------------------------------------------------ */
+
+export class MigrationPreconditionError extends Error {
+  constructor(
+    message: string,
+    public readonly remediation: string,
+  ) {
+    super(message);
+    this.name = 'MigrationPreconditionError';
+  }
+}
+
+/**
+ * Verify target preconditions before writing any data.
+ *
+ * Checks:
+ * 1. pgvector extension installed.
+ * 2. User-data tables are empty (unless --allow-non-empty).
+ */
+export async function checkTargetPreconditions(
+  target: MigrationTarget,
+  allowNonEmpty: boolean,
+  tablesToMigrate: string[],
+): Promise<void> {
+  const hasVector = await target.hasPgvector();
+  if (!hasVector) {
+    throw new MigrationPreconditionError(
+      'Target Postgres does not have the pgvector extension installed.',
+      'Run: CREATE EXTENSION IF NOT EXISTS vector; — or use the pgvector/pgvector:pg17 Docker image.',
+    );
+  }
+
+  if (!allowNonEmpty) {
+    // Check the first non-empty user-data table.
+    for (const table of tablesToMigrate) {
+      const n = await target.count(table);
+      if (n > 0) {
+        throw new MigrationPreconditionError(
+          `Target table "${table}" already contains ${n.toString()} rows.`,
+          'Pass --allow-non-empty to overwrite existing data (upsert semantics), ' +
+            'or point to an empty target database.',
+        );
+      }
+    }
+  }
+}
+
+/* ------------------------------------------------------------------ */
+/*  Core migration runner                                               */
+/* ------------------------------------------------------------------ */
+
+/**
+ * Run the tier migration.
+ *
+ * @param source  Adapter for reading source rows.
+ * @param target  Adapter for writing rows to target.
+ * @param opts    Migration options.
+ * @param sourceHasVector  True if the source tier supports vector columns.
+ */
+export async function runMigrateTier(
+  source: MigrationSource,
+  target: MigrationTarget,
+  opts: MigrateTierOptions,
+  sourceHasVector = false,
+): Promise<MigrateTierResult> {
+  const { dryRun, allowNonEmpty, batchSize, onProgress } = opts;
+
+  const tablesToMigrate = getMigrationOrder();
+
+  // Preflight: gather row counts from source.
+  onProgress('[migrate-tier] Gathering source row counts...');
+  const sourceCounts = new Map<string, number>();
+  for (const table of tablesToMigrate) {
+    const n = await source.count(table);
+    sourceCounts.set(table, n);
+  }
+
+  // Log preflight summary.
+  onProgress('[migrate-tier] Tables to migrate:');
+  for (const table of tablesToMigrate) {
+    const n = sourceCounts.get(table) ?? 0;
+    onProgress(`  ${table}: ${n.toString()} rows`);
+  }
+  for (const skipped of SKIP_TABLES) {
+    onProgress(`  ${skipped}: SKIPPED (ephemeral/environment-specific)`);
+  }
+
+  // Vector column notice.
+  if (!sourceHasVector) {
+    onProgress(
+      '[migrate-tier] NOTE: Source tier has no pgvector support. ' +
+        'insights.embedding will be NULL on all migrated rows.',
+    );
+  }
+
+  if (dryRun) {
+    onProgress('[migrate-tier] DRY RUN — no writes will be made.');
+    const tables: TableMigrationResult[] = tablesToMigrate.map((t) => ({
+      table: t,
+      rowsMigrated: 0,
+      skipped: false,
+    }));
+    for (const skipped of SKIP_TABLES) {
+      tables.push({ table: skipped, rowsMigrated: 0, skipped: true, skipReason: 'ephemeral' });
+    }
+    return { tables, totalRows: 0, dryRun: true };
+  }
+
+  // Check preconditions before writing.
+  await checkTargetPreconditions(target, allowNonEmpty, tablesToMigrate);
+
+  const results: TableMigrationResult[] = [];
+  let totalRows = 0;
+
+  for (const table of tablesToMigrate) {
+    const sourceCount = sourceCounts.get(table) ?? 0;
+
+    if (sourceCount === 0) {
+      onProgress(`[migrate-tier] ${table}: 0 rows — skipping.`);
+      results.push({ table, rowsMigrated: 0, skipped: false });
+      continue;
+    }
+
+    onProgress(`[migrate-tier] ${table}: migrating ${sourceCount.toString()} rows...`);
+
+    let offset = 0;
+    let tableTotal = 0;
+    let lastSuccessfulId: string | undefined;
+
+    try {
+      while (offset < sourceCount) {
+        const rows = await source.readTable(table, { limit: batchSize, offset });
+        if (rows.length === 0) break;
+
+        const normalised = rows.map((row) => normaliseSourceRow(table, row, sourceHasVector));
+
+        await target.upsertBatch(table, normalised);
+
+        lastSuccessfulId = rows[rows.length - 1]?.['id'] as string | undefined;
+        tableTotal += rows.length;
+        offset += rows.length;
+
+        onProgress(
+          `[migrate-tier] ${table}: ${tableTotal.toString()}/${sourceCount.toString()} rows written`,
+        );
+      }
+    } catch (err) {
+      const errMsg = err instanceof Error ? err.message : String(err);
+      throw new Error(
+        `[migrate-tier] Failed on table "${table}" after ${tableTotal.toString()} rows ` +
+          `(last id: ${lastSuccessfulId ?? 'none'}). Error: ${errMsg}\n` +
+          `Remediation: Re-run with --allow-non-empty to resume (upsert is idempotent).`,
+      );
+    }
+
+    results.push({ table, rowsMigrated: tableTotal, skipped: false });
+    totalRows += tableTotal;
+    onProgress(`[migrate-tier] ${table}: done (${tableTotal.toString()} rows).`);
+  }
+
+  // Add skipped table records.
+  for (const skipped of SKIP_TABLES) {
+    results.push({
+      table: skipped,
+      rowsMigrated: 0,
+      skipped: true,
+      skipReason: 'ephemeral or environment-specific — re-issue on target',
+    });
+  }
+
+  onProgress(`[migrate-tier] Complete. ${totalRows.toString()} total rows migrated.`);
+  return { tables: results, totalRows, dryRun: false };
+}