Expose Unused Index Fields

[nloding]

Problem

The following index fields exist in the data structure but have no public API:

Field	Description	Status
final_mat_sig	Final material signature	Stored but unused
stored_line_code	Stored line code	Stored but unused
home_pawn_data	Home pawn signature	Stored but unused
Custom flags (6 bits)	Available for custom use	Defined, no API
base_type	Database type	Stored but unused

Solution

Consider exposing these fields through getter/setter methods if they would be useful for users.

File

src/index.rs

Priority

Low - may not be needed