fix: reduce MAX_TABLE_NAME_LENGTH from 64 to 63

PostgreSQL's limit is 63 (NAMEDATALEN-1). MySQL allows 64 but 63
is safe for both. Prevents silent truncation on PostgreSQL.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: dimitri-yatsenko

src/datajoint/declare.py

@@ -52,7 +52,7 @@
 # Get SQL mapping for core types
 CORE_TYPE_SQL = {name: sql_type for name, (_, sql_type) in CORE_TYPES.items()}
 
-MAX_TABLE_NAME_LENGTH = 64
+MAX_TABLE_NAME_LENGTH = 63  # PostgreSQL NAMEDATALEN-1; MySQL allows 64 but 63 is safe for both
 CONSTANT_LITERALS = {
     "CURRENT_TIMESTAMP",
     "NULL",