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/surreal/test1.nim

@@ -0,0 +1,49 @@
+import std/asyncdispatch
+import std/httpclient
+import std/streams
+import std/json
+import ../../src/allographer/connection
+import ../../src/allographer/query_builder
+import ../../src/allographer/schema_builder
+
+proc main() {.async.} =
+  let rdb = dbOpen(SurrealDB, "ns", "database", "user", "pass", "http://surreal", 8000, shouldDisplayLog=true).await
+  
+  rdb.raw("""
+    REMOVE TABLE `test`
+  """).exec().await
+
+  rdb.raw("""
+    DEFINE TABLE `test` SCHEMAFULL;
+    DEFINE FIELD `bool` ON TABLE `test` TYPE bool;
+    DEFINE FIELD `int` ON TABLE `test` TYPE int;
+    DEFINE FIELD `float` ON TABLE `test` TYPE decimal;
+    DEFINE FIELD `str` ON TABLE `test` TYPE string;
+    DEFINE FIELD `data` ON TABLE `test` TYPE string | NONE;
+    DEFINE FIELD `object` ON TABLE `test` TYPE object | NONE FLEXIBLE;
+  """).exec().waitFor
+
+  echo rdb.table("test").columns().waitFor
+
+  rdb.raw("""
+    INSERT INTO `test` {bool:?, int:?, float:?, str:?, object:?}
+  """, %*[true, 1, 1.1, "alice", {"bool": false, "int": 2, "float": 2.1, "str": "two"}]).exec().waitFor
+
+  echo rdb.raw("""
+    SELECT * FROM `test`
+  """).get().waitFor
+
+  let client = newAsyncHttpClient()
+  var veryLongText = ""
+  var response = client.getContent("https://bible-api.com/genesis+1:1-31").await.parseJson
+  veryLongText.add(response["text"].getStr)
+  response = client.getContent("https://bible-api.com/genesis+2:1-25").await.parseJson
+  veryLongText.add(response["text"].getStr)
+  response = client.getContent("https://bible-api.com/genesis+3:1-24").await.parseJson
+  veryLongText.add(response["text"].getStr)
+
+  rdb.table("test").insert(%*{"bool":false, "int":2, "float":2.1, "str": veryLongText}).waitFor
+
+  echo rdb.select("bool", "int", "float", "str").table("test").get().waitFor
+
+main().waitFor