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/surrealDb.nim

@@ -0,0 +1,17 @@
+import std/asyncdispatch
+import std/json
+import ../src/allographer/connection
+import ../src/allographer/query_builder
+
+
+let db = dbOpen(SurrealDB, "test", "test", "user", "pass", "http://surreal", 8000, 10, 30, true, true).waitFor()
+db.raw("DELETE FROM account").exec().waitFor
+echo db.raw("INFO FOR DB").get().waitFor
+
+for _ in 0..3:
+  db.raw("CREATE account SET name = 'ACME Inc', created_at = time::now()").exec().waitFor
+
+let resp = db.raw("SELECT * from account").get().waitFor
+for row in resp:
+  echo row
+  echo row["id"].getStr