Incorrect Points Required for Skill Advancement

[Halifay]

Description: The amount of points required to advance to the next level is displayed as 0 for skills at very high levels, which is often observed in combat skills. Considering the known formula for calculating the exact points needed for any level, this appears to be a bug that could be easily addressed.

Steps to Reproduce:

Train a skill to a very high level (commonly observed in combat skills).

Observe the points required to advance to the next level.

Expected Behavior: The points required to reach the next level should be displayed accurately according to the known formula.

Actual Behavior: The points required to reach the next level are displayed as 0.

Additional Information:

Version: 51.01 adventure beta

[quietust]

The issue is that the XP threshold is being fetched from the skill_rating enum type defined in library/xml/df.units.xml rather than being calculated dynamically, so it only has meaningful values for levels up to Legendary+4 (19).