Target Ancestors' Rage by adjacent enemy density

[Wellwisher533]

Adds a dedicated strict ally target mode for Ancestors' Rage. It selects a living, targetable allied creature with at least two adjacent living foes, including party allies, the player, spirits and pets, minions, and friendly NPCs or summons. The mode is wired through regular HeroAI, BuildMgr/headless, and legacy SkillManager without changing AllyMartial behavior for other skills. Verification: all seven changed Python files compile; eight focused local targeting and wiring tests passed; Ancestors' Rage targeting was confirmed working in-game. Local test scripts are intentionally excluded from this PR.

[apoguita]

there is already a routine that handled balled up targets, if your behaviour is more complete and reliable, have it replace the current instead of having a duplicate one

[Wellwisher533]

Addressed in 38e2095. I generalized the existing Routines.Targeting clustered picker so it can score an explicit candidate set and distinguish an enemy center (excluded from its own nearby-enemy count) from an allied center (all adjacent enemies count). The existing enemy-target defaults and callers are preserved. Ancestors' Rage now only assembles its valid allied/summoned candidates and delegates scoring to that shared routine, removing the duplicate loop. Focused compatibility tests were run locally and remain excluded from the PR.