skillListingBudgetFraction: raising limit always overshoots new limit by ~1%

Bug Description

Raising skillListingBudgetFraction per /doctor's recommendation always causes skill listing usage to overshoot the new limit by ~1%. The fix /doctor suggests is self-defeating.

Steps to Reproduce

1. skillListingBudgetFraction = 1% → skill listing usage = 1.9% → /doctor warns: "raise skillListingBudgetFraction (currently 1%)", recommends 2%
2. Raise skillListingBudgetFraction to 2% per recommendation
3. Skill listing usage jumps to 2.9% → /doctor warns again with same message

Expected Behavior

skillListingBudgetFraction should act as a hard cap. Usage should always be ≤ the configured limit. After raising the limit, the warning should either resolve or recommend an accurate new value.

Actual Behavior

Each time the limit is raised, the system loads additional skill descriptions that were previously truncated. Those newly-loaded descriptions push usage 0.9% over the new limit, so the warning persists regardless of what value is set.

The warning message updates to recommend an even higher budget, just 0.1% over the reported usage.

Additional Context

• skillListingBudgetFraction was previously stored as a string "2%" (validation error), fixed to 0.02 (number) — behaviour observed both before and after this fix
• The overshoot is consistent (~1% each time), suggesting the system loads one additional "batch" of descriptions whenever headroom increases
• /doctor recommended value triggers the overshoot, making the recommendation impossible to satisfy