Add veterancy-based target filtering for weapons and warheads

[Flactine]

This PR introduces veterancy-based filtering for both weapon targeting and warhead effect application.

---

1. Weapon target filtering by target veterancy

Weapons can now restrict which targets they are allowed to attack based on the target’s veterancy level.
This affects both weapon firing eligibility and weapon selection logic (except for special cases where weapon selection is fixed by the engine).

New INI options:

[SOMEWEAPON]             ; WeaponType
CanTarget.MinVeterancy=0.0   ; float, default 0.0
CanTarget.MaxVeterancy=   ; float, default to [General] -> VeteranCap

• 0.0 = Rookie
• 1.0 = Veteran
• 2.0 = Elite

Targets whose veterancy falls outside the specified range will not be considered valid targets for the weapon.

Units with Trainable=no are always treated as having Veterancy = 0.0 (Rookie) for the purpose of these checks.

---

2. Warhead effect filtering by target veterancy

Warheads can now conditionally apply their effects based on the target’s veterancy level.
Unlike weapon filtering, this logic does not affect whether a weapon can fire, but instead determines whether the warhead’s effects will be applied after detonation.

New INI options:

[SOMEWARHEAD]               ; WarheadType
AffectsAboveVeterancy=0.0   ; float, default 0.0
AffectsBelowVeterancy=   ; float, default to [General] -> VeteranCap

• The warhead will only affect targets whose veterancy lies within the specified range.
• If the target has zero health remaining, this check is bypassed (consistent with existing health-based warhead conditions).
• Units with Trainable=no are treated as Veterancy = 0.0.

---

---

---

本次更新新增了基于目标等级（Veterancy）的筛选逻辑，分别作用于武器攻击判定和弹头效果生效判定。

---

1. 基于目标等级的武器筛选

武器现在可以根据目标单位的经验等级，决定是否允许对其进行攻击。
该逻辑不仅影响武器能否开火，也会影响武器选择流程（部分引擎强制固定选择的特殊情况除外）。

新增 INI 选项（WeaponType）：

[SOMEWEAPON]             ; WeaponType
CanTarget.MinVeterancy=0.0   ; 浮点数，默认 0.0
CanTarget.MaxVeterancy=   ; 浮点数，默认 [General] -> VeteranCap

经验等级对应关系如下：

• 0.0 = 新兵
• 1.0 = 老兵
• 2.0 = 精英

当目标的经验等级不在该区间内时，武器将不会将其视为可攻击目标。

拥有 Trainable=no 的单位会被直接视为 Veterancy = 0.0（新兵） 进行判断。

---

2. 基于目标等级的弹头效果筛选

弹头现在可以根据目标单位的经验等级，决定爆炸后是否对其产生效果。
与武器筛选不同，此逻辑不影响武器是否开火，而是作用于爆炸结算阶段。

新增 INI 选项：

[SOMEWARHEAD]               ; WarheadType
AffectsBelowVeterancy=0.0   ; 浮点数，默认 0.0
AffectsAboveVeterancy=   ; 浮点数，默认 [General] -> VeteranCap

• 只有经验等级位于指定区间内的目标才会受到弹头效果影响
• 当目标生命值为 0 时，该检查会被跳过（与现有生命值条件保持一致）
• Trainable=no 的单位同样被视为 Veterancy = 0.0

[github-actions]

Nightly build for this pull request:

• compiled-dll-7c80b01f6ff6decf922c9e4c9273c92894bff582.zip
  These artifacts will expire in 90 days and will not be available for download after that time.

This comment is automatic and is meant to allow guests to get latest nightly builds for this pull request without registering. It is updated on every successful build.

[Coronia]

maybe it's better to put veterancy in an enum, so it can be represented in a clearer way than having to remember what 0.0, 1.0 and 2.0 stand for, and could be reused in the future

[Coronia]

these 2 lines should be put at the end of this section

[ZivDero]

It looks solid overall, but I can't help shake the feeling that the "can target" and "can affect" stuff is getting a bit spaghetti. Could combine it all into single "can target" and "can affect" functions (with subfunctions for the various logics). Though this is not the fault of this specific PR.

[ZivDero]

Capitalization please.