refactor: 删除引擎 Tick 中 ReleaseAltitude → _disperseHeight fallback

AGENTS.md

@@ -93,6 +93,31 @@ pwsh -Command "dotnet test test/unit/CounterDrone.Core.Tests/ --filter 'FullyQua
 pwsh -Command "dotnet test test/unit/CounterDrone.Core.Tests/"
 ```
 
+## 8. No Hardcoded Defaults or Fallbacks
+
+**Every parameter must come from configuration. If a required value is missing, fail explicitly — never silently substitute a default.**
+
+Good:
+```csharp
+if (unit.CruiseSpeed <= 0)
+    throw new InvalidOperationException($"单元 {unit.Id}: CruiseSpeed 必须 > 0");
+```
+
+Bad:
+```csharp
+float speed = unit.CruiseSpeed > 0 ? unit.CruiseSpeed : 55f;  // 55f 是哪来的？
+float mv = unit.MuzzleVelocity ?? 800f;                         // 为什么是 800？
+float alt = unit.ReleaseAltitude > 0 ? unit.ReleaseAltitude : threat.Altitude + 500f; // 500？
+```
+
+This applies to:
+- `??` operator with arbitrary numbers (55f, 800f, 1000f, 3, etc.)
+- Ternary `> 0 ? x : default` patterns
+- `Math.Max(0.1f, x)` to prevent division by zero — instead validate the input before the division
+- `if (fireTime < 0.1f) fireTime = 0.1f` — instead skip the event and report the failure
+
+Physics constants (9.81f, 3.6f, π) and documented model parameters (Phase 2 cutoff = 30s) are NOT arbitrary defaults — they are legitimate parts of the physical model.
+
 ---
 
 **These guidelines are working if:** fewer unnecessary changes in diffs, fewer rewrites due to overcomplication, and clarifying questions come before implementation rather than after mistakes.

src/CounterDrone.Core/Simulation/SimulationEngine.cs

@@ -165,9 +165,7 @@ namespace CounterDrone.Core.Simulation
 
                 if (platform.PlatformType == Models.PlatformType.AirBased && platform.Ready)
                 {
-                    // 空基：下令飞往投放点（投放点 = 目标正上方，ReleaseAltitude 高度）
-                    var releaseAlt = platform.ReleaseAltitude > 0 ? platform.ReleaseAltitude : _disperseHeight;
-                    platform.CommandFlyTo(fe.TargetX, releaseAlt, fe.TargetZ);
+                    platform.CommandFlyTo(fe.TargetX, platform.ReleaseAltitude, fe.TargetZ);
                 }
                 else if (platform.Ready)
                 {