feat(capture): 重构捕捉系统，实现状态倍率计算和保底机制

logic/service/fight/info/ctx.go

@@ -0,0 +1,50 @@
+package info
+
+import "math/rand"
+
+// PlayerCaptureContext 用户捕捉上下文（每次登录创建）
+type PlayerCaptureContext struct {
+	Random      *rand.Rand
+	Denominator int         // 统一分母=1000
+	DecayFactor float64     // 衰减系数
+	MinDecayNum int         // 衰减分子最小值
+	Guarantees  map[int]int // 按分母分组的保底分子 map[denominator]numerator
+}
+
+// Roll 通用概率判定（带共享保底）
+func (c *PlayerCaptureContext) Roll(numerator, denominator int) (bool, float64, float64) {
+	if denominator <= 0 {
+		return false, 0, 0
+	}
+
+	base := float64(numerator) / float64(denominator)
+	bonus := float64(c.getGuaranteeNumerator(denominator)) / float64(denominator)
+	total := base + bonus
+	if total > 1.0 {
+		total = 1.0
+	}
+
+	success := c.Random.Float64() < total
+
+	if success {
+		c.resetGuarantee(denominator)
+	} else {
+		c.increaseGuarantee(denominator)
+	}
+
+	return success, base * 100, bonus * 100
+}
+
+// 保底操作
+func (c *PlayerCaptureContext) getGuaranteeNumerator(denominator int) int {
+	if num, ok := c.Guarantees[denominator]; ok {
+		return num
+	}
+	return 0
+}
+func (c *PlayerCaptureContext) increaseGuarantee(denominator int) {
+	c.Guarantees[denominator]++
+}
+func (c *PlayerCaptureContext) resetGuarantee(denominator int) {
+	c.Guarantees[denominator] = 0
+}