Prevent ACE guns from hitting their own contraptions

[Ally-for-Hire]

Idea

Look into how ACF-3 does their self-filtering, port that as it applies, and remove legacy fixes that would manually offset the bullets. We can use AI to find the specifics as they pertain to ACE, and then we can create an implementation plan for it to execute.

Description

ACE projectile filters previously excluded only the firing gun, so moving-shot traceback could re-enter the firing vehicle and damage its own armor. This ports ACF-3's contraption-wide projectile filtering approach and corrects ACE's projectile-origin handling. We are diverging slightly from theirs by implementing a 3 tick grace window, then back to normal function, so bullet's can still hit your vehicle after they've left it.

Summary

• Maintain a live bullet filter for every CFW contraption, including entity add/remove lifecycle updates.
• Pass the current contraption filter into each gun shot without adding a second per-shot copy.
• Preserve that filter for flechettes and AP/HE/HEAT cluster bomblets.
• Avoid duplicating the firing gun when the shared bullet creation path finalizes the filter.
• Keep conventional projectiles at the physical muzzle; retain parent velocity in flight instead of shifting the spawn position.
• Include 3-tick grace period for this filter to be active, then disable it after.

[Ally-for-Hire]

works ingame, i approve for merge, will wait a few days

[Ally-for-Hire]

code looks good