Address PR #52 review: IsComponent gate + inout cast

- inout ternary cast to int16_t (flecs field type; WERROR-safe).
- TickParameterSnapshot gains IsComponent (unmanaged + implements
  IComponent via existing helper); IsRunnable rejects non-components
  (BadParam fixture proves Register -> -2).

managed/Engine.Analyzers/ComponentSystemGenerator.cs

@@ -242,7 +242,8 @@ public sealed class ComponentSystemGenerator : IIncrementalGenerator
                 pars.Add(new TickParameterSnapshot(
                     kind,
                     p.Type.ToDisplayString(SymbolDisplayFormat.FullyQualifiedFormat),
-                    p.Name));
+                    p.Name,
+                    kind != TickRefKind.None && IsUnmanagedComponent(p.Type, iComponent)));
             }
 
             ticks.Add(new TickSignatureSnapshot(
@@ -378,6 +379,16 @@ public sealed class ComponentSystemGenerator : IIncrementalGenerator
         return false;
     }
 
+    // A Tick component parameter must be usable as a native column: an
+    // unmanaged value type implementing IComponent. Checked with the
+    // existing Implements helper; anything else is not a component.
+    private static bool IsUnmanagedComponent(ITypeSymbol type, INamedTypeSymbol iComponent)
+    {
+        return type.IsUnmanagedType
+            && type is INamedTypeSymbol named
+            && Implements(named, iComponent);
+    }
+
     private static ImmutableArray<string> ReadPhases(ISymbol sym)
     {
         var builder = ImmutableArray.CreateBuilder<string>();
@@ -714,6 +725,11 @@ public sealed class ComponentSystemGenerator : IIncrementalGenerator
                 return false;
             }
 
+            if (!p.IsComponent)
+            {
+                return false;
+            }
+
             components.Add(p);
         }
 

managed/Engine.Analyzers/Models.cs

@@ -29,7 +29,8 @@ internal enum TickRefKind
 internal sealed record TickParameterSnapshot(
     TickRefKind RefKind,
     string TypeName,
-    string Name);
+    string Name,
+    bool IsComponent);
 
 /// <summary>One user Tick overload: parameters + UpdateInPhase phases.</summary>
 internal sealed record TickSignatureSnapshot(

managed/Engine.Tests/GeneratorDriverTests.cs

@@ -80,6 +80,19 @@ public static unsafe class GeneratorDriverTests
 
             public void Tick(ref DupTerm self, in Health a, in Health b) => self.V++;
         }
+
+        // Non-component ref parameter: Register must return -2.
+        public struct PlainData
+        {
+            public int V;
+        }
+
+        public partial struct BadParam : IComponent
+        {
+            public int V;
+
+            public void Tick(ref BadParam self, ref PlainData other) => self.V++;
+        }
         """;
 
     public static int Run()
@@ -99,7 +112,7 @@ public static unsafe class GeneratorDriverTests
 
         failures += CheckMover(asm);
         failures += CheckBomb(asm);
-        foreach (var name in new[] { "Fx.ByValue", "Fx.DoubleDt", "Fx.DupTerm" })
+        foreach (var name in new[] { "Fx.ByValue", "Fx.DoubleDt", "Fx.DupTerm", "Fx.BadParam" })
         {
             failures += Check(CallRegister(asm, name) == -2, $"{name}.Register -> -2 (unrunnable shape)");
         }

native/bridge/src/generic_systems.cpp

@@ -169,8 +169,8 @@ auto GenericSystems::register_system(ecs_world_t* world, const char* name,
     // Owned components only: every field is then a real column array
     // (an inherited/shared match would be a single pointer, not an array).
     qd.terms[i].src.id = EcsSelf;
-    qd.terms[i].inout =
-        (access[i] == ENGINE_ABI_ACCESS_IN) ? EcsIn : EcsInOut;
+    qd.terms[i].inout = static_cast<int16_t>(
+        (access[i] == ENGINE_ABI_ACCESS_IN) ? EcsIn : EcsInOut);
     sys.sizes[i] = static_cast<int32_t>(ti->size);
   }
   qd.cache_kind = EcsQueryCacheAuto;