Preserve long PostgreSQL index expressions

[Josh-McFarlin]

Summary

Preserves PostgreSQL index expressions longer than the 63-byte identifier limit during introspection.

What changed

• Casts pg_attribute.attname to text before coalescing it with pg_get_indexdef.
• Adds a synthetic PGlite regression for an 85-byte index expression.

Validation

• The focused regression fails before the cast by returning a 63-byte truncated expression.
• The focused regression passes after the cast.

Stack

This PR targets the existing 0.32.4 release head so the release version remains the stack parent.

Rollout and rollback

This PR does not publish a package or update a consumer. Reverting it restores the prior introspection query.

~ written by Replit Agent