Fix bullet trajectory when ship is rotating

Calculate velocity at bullet spawn point (8.4 units from center) instead
of ship center. Accounts for tangential velocity from angular rotation
using cross product: velocity_at_spawn = linear + (angular × offset).

This fixes bullets appearing to drift when ship is moving and rotating.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/ship/ship.ts

@@ -697,11 +697,29 @@ export class Ship {
         }
 
         if (this._weapons && this._ship && this._ship.physicsBody) {
-            // Calculate projectile velocity: ship forward + ship velocity
-            const shipVelocity = this._ship.physicsBody.getLinearVelocity();
+            // Get ship velocities
+            const linearVelocity = this._ship.physicsBody.getLinearVelocity();
+            const angularVelocity = this._ship.physicsBody.getAngularVelocity();
+
+            // Spawn offset in local space (must match weaponSystem.ts)
+            const localSpawnOffset = new Vector3(0, 0.5, 8.4);
+
+            // Transform spawn offset to world space (direction only)
+            const worldSpawnOffset = Vector3.TransformNormal(
+                localSpawnOffset,
+                this._ship.getWorldMatrix()
+            );
+
+            // Calculate tangential velocity at spawn point: ω × r
+            const tangentialVelocity = angularVelocity.cross(worldSpawnOffset);
+
+            // Velocity at spawn point = linear + tangential
+            const velocityAtSpawn = linearVelocity.add(tangentialVelocity);
+
+            // Final projectile velocity: forward direction + spawn point velocity
             const projectileVelocity = this._ship.forward
                 .scale(200000)
-                .add(shipVelocity);
+                .add(velocityAtSpawn);
 
             this._weapons.fire(this._ship, projectileVelocity);
         }

src/ship/weaponSystem.ts

@@ -83,7 +83,7 @@ export class WeaponSystem {
         // Create projectile instance
         const ammo = new InstancedMesh("ammo", this._ammoBaseMesh as Mesh);
         ammo.parent = shipTransform;
-        ammo.position.y = 0.1;
+        ammo.position.y = 0.5;
         ammo.position.z = 8.4;
 
         // Detach from parent to move independently