PostgreSQL index names share the schema-wide relation namespace, so a
reused name makes CREATE INDEX IF NOT EXISTS silently skip the duplicate.
Add duplicate_index_name rule (enforce by default) covering indexes and
PK/unique constraint backing indexes.
* Introduce tests for PostgreSQL data types and keywords.
* Implement tests for reflect utility functions.
* Ensure consistency and correctness of type conversions and keyword mappings.
* Validate behavior for various edge cases and input types.
warkanum