feat(db): перевести хранилище с SQLite на PostgreSQL

При старте backend накатывает схему PostgreSQL 18 и, если база пустая, один раз импортирует mikrotik.db с тома. Повторный старт не копирует данные. Бэкап в UI идёт через pg_dump.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/src/db/migrate.ts

@@ -0,0 +1,43 @@
+import { readFileSync } from "node:fs"
+import { dirname, join } from "node:path"
+import { fileURLToPath } from "node:url"
+import type { Pool } from "pg"
+
+const MIGRATION_ID = "0000_postgresql"
+
+function migrationsDir(): string {
+  const here = dirname(fileURLToPath(import.meta.url))
+  const candidates = [
+    join(here, "..", "..", "drizzle"),
+    join(process.cwd(), "drizzle"),
+    join(process.cwd(), "backend", "drizzle"),
+  ]
+  for (const dir of candidates) {
+    try {
+      readFileSync(join(dir, `${MIGRATION_ID}.sql`), "utf8")
+      return dir
+    } catch {
+      /* try next */
+    }
+  }
+  throw new Error("Не найден backend/drizzle/0000_postgresql.sql")
+}
+
+export async function applySqlMigrations(pool: Pool): Promise<void> {
+  await pool.query(`
+    CREATE TABLE IF NOT EXISTS schema_migrations (
+      id TEXT PRIMARY KEY,
+      applied_at TIMESTAMPTZ NOT NULL DEFAULT now()
+    )
+  `)
+  const { rows } = await pool.query<{ id: string }>(
+    `SELECT id FROM schema_migrations WHERE id = $1`,
+    [MIGRATION_ID],
+  )
+  if (rows.length > 0) return
+  const sql = readFileSync(join(migrationsDir(), `${MIGRATION_ID}.sql`), "utf8")
+  await pool.query(sql)
+  await pool.query(`INSERT INTO schema_migrations (id) VALUES ($1) ON CONFLICT (id) DO NOTHING`, [
+    MIGRATION_ID,
+  ])
+}