feat(clients): add nim-allographer client with BaraDB driver support

- Pure Nim wire protocol client (async + sync, no C FFI)
- Query Builder: fluent API, SQL generator, execution, transactions
- Schema Builder: create/alter/drop tables, column operations
- Connection pool with aging and timeout handling
- ORM integration via compile-time DB_BARADB switch
- Tests: test_open, test_query
- Documentation: README.md, PLAN_BARADB.md

clients/nim-allographer/example/database/seeder/production.nim

@@ -0,0 +1,14 @@
+import std/asyncdispatch
+import std/os
+import ./data/user_seeder
+import ./data/post_seeder
+
+proc seed() =
+  let env = getEnv("APP_ENV")
+  if env != "production":
+    raise newException(Exception, "This command is only available in the production environment")
+
+  userSeeder().waitFor()
+  postSeeder().waitFor()
+
+seed()