surreal: improve schema generation and error handling

Body
- Add `responseMessage(JsonNode)` helper and use it to produce clearer, robust error messages when parsing SurrealDB `info()` responses.
- Harden exec/execThenSaveHistory to check presence/type of `status` and to raise errors using `responseMessage` instead of assuming keys.
- Treat Surreal `id` field as a special case: skip generating autoincrement definitions for `id` (avoid defining increments on Surreal primary id) and adjust createIncrements/createInt behavior.
- Map Surreal `object` type to Nim `JsonNode` in `create_schema` generation.
- Update test `tests/surrealdb/test_create_schema.nim` to use `index` as the increments column in fixtures and assert generated schema accordingly.
- Files changed: src/allographer/schema_builder/queries/surreal/schema_utils.nim, src/allographer/schema_builder/queries/surreal/sub/create_column_query.nim, src/allographer/schema_builder/usecases/surreal/create_schema.nim, tests/surrealdb/test_create_schema.nim.

Rationale
Improve robustness when consuming SurrealDB metadata and ensure generated Nim schema/types and column-definition SQL are consistent and safe for common edge cases.

Author: dumblepy

src/allographer/schema_builder/queries/surreal/schema_utils.nim

@@ -20,6 +20,17 @@ proc notAllowedType*(typ:string) =
   raise newException(DbError, &"type {typ} is not allowed")
 
 
+proc responseMessage(node: JsonNode): string =
+  if node.kind == JObject:
+    for key in ["detail", "information", "result", "message", "error"]:
+      if node.hasKey(key):
+        let value = node[key]
+        if value.kind == JString:
+          return value.getStr()
+        return value.pretty
+  return node.pretty
+
+
 # ==================================================
 # SurrealDB
 # ==================================================
@@ -60,8 +71,8 @@ proc execThenSaveHistory*(rdb:SurrealConnections, tableName:string, queries:seq[
     for query in queries:
       let resp = rdb.raw(query).info().waitFor
       for row in resp:
-        if row["status"].getStr != "OK":
-          raise newException(DbError, row["detail"].getStr)
+        if row.hasKey("status") and row["status"].kind == JString and row["status"].getStr != "OK":
+          raise newException(DbError, responseMessage(row))
     isSuccess = true
   except DbError:
     echo getCurrentExceptionMsg()
@@ -91,10 +102,10 @@ proc execThenSaveHistory*(rdb:SurrealConnections, tableName:string, query:string
   try:
     let resp = rdb.raw(query).info().waitFor
     if resp.kind == JObject:
-      raise newException(DbError, resp["information"].getStr)
+      raise newException(DbError, responseMessage(resp))
     for row in resp:
-      if row["status"].getStr != "OK":
-        raise newException(DbError, row["detail"].getStr)
+      if row.hasKey("status") and row["status"].kind == JString and row["status"].getStr != "OK":
+        raise newException(DbError, responseMessage(row))
     isSuccess = true
   except DbError:
     echo getCurrentExceptionMsg()

src/allographer/schema_builder/queries/surreal/sub/create_column_query.nim

@@ -47,10 +47,17 @@ proc autoIncrementValueExpr(table: Table, column: Column): string =
   &"(SELECT `max_index` FROM `_autoincrement_sequences` WHERE `table` = \"{table.name}\" AND `column` = \"{column.name}\" LIMIT 1)[0].max_index + 1"
 
 
+proc isSurrealIdField(column: Column): bool =
+  column.name == "id"
+
+
 # =============================================================================
 # int
 # =============================================================================
 proc createIncrementsColumn(column:Column, table:Table):seq[string] =
+  if isSurrealIdField(column):
+    return @[]
+
   let nextIndexExpr = autoIncrementValueExpr(table, column)
   result.add(&"""
     INSERT INTO `_autoincrement_sequences` {{table: "{table.name}", column: "{column.name}", max_index: 0}};
@@ -67,6 +74,9 @@ proc createIntColumn(column:Column, table:Table):seq[string] =
   var assertClause = ""
 
   if column.isAutoIncrement:
+    if isSurrealIdField(column):
+      return @[]
+
     let nextIndexExpr = autoIncrementValueExpr(table, column)
     query.add(&"""
       INSERT INTO `_autoincrement_sequences` {{table: "{table.name}", column: "{column.name}", max_index: 0}};

src/allographer/schema_builder/usecases/surreal/create_schema.nim

@@ -66,6 +66,8 @@ proc generateSchemaCode(tablesInfo: Table[string, seq[tuple[name: string, typ: s
           "int"
         of "string", "datetime":
           "string"
+        of "object":
+          "JsonNode"
         of "bool":
           "bool"
         of "decimal", "float":

tests/surrealdb/test_create_schema.nim

@@ -26,13 +26,13 @@ suite "Schema output after migration":
 
     rdb.create(
       table("int_relation", [
-        Column.increments("id")
+        Column.increments("index")
       ]),
       table("str_relation", [
         Column.uuid("uuid")
       ]),
       table("test_schema_output", [
-        Column.increments("id"),
+        Column.increments("index"),
         Column.integer("integer"),
         Column.smallInteger("smallInteger"),
         Column.mediumInteger("mediumInteger"),