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/src/allographer/utils/snake_to_camel.nim

@@ -0,0 +1,7 @@
+import std/strutils
+import std/sequtils
+
+
+proc snakeToCamel*(s: string): string =
+  ## convert snake_case to CamelCase
+  result = s.split("_").mapIt(it.capitalizeAscii()).join("")