Add event AI target priority shifts

docs/GODOT_4_6_MIGRATION.md

@@ -53,6 +53,7 @@ powershell -NoProfile -ExecutionPolicy Bypass -File tools\check_godot46_readines
 - `unit_defeated` scenario events fire named-unit reactions before final battle status checks, including Yan Liang and Wen Chou defeat dialogue.
 - `set_objective` scenario events show concrete objective-update logs, play a UI confirmation sound, refresh the HUD immediately, and briefly show the objective notice panel.
 - `withdraw_unit` and `withdraw_units` scenario events remove living targets from the battlefield without marking them defeated.
+- `set_ai_target_priority` scenario events retune enemy focus during battle and show target-focus feedback unless marked silent.
 - Movement-triggered supply cache events grant battle inventory items with pickup feedback, and the items persist only after victory.
 - The Threat toggle or `Y` key shows enemy physical and hostile tactic reach, hovered threatened tiles name the threatening units, and occupied player tiles show physical damage/hit estimates plus hostile tactic damage or status hints.
 - Area tactics such as Blaze, Great Mend, and Poison Mist highlight affected cells, apply only to valid targets in the area, and spend MP once per cast.