Track PhysX integration follow-ups after #3025

[luzhuang]

Context

PR #3025 brings the current engine-side PhysX integration much closer to the semantics exposed by galacean/physX.js. While reviewing it against the local physX.js binding, a few worthwhile follow-ups came up that are not merge blockers for #3025 and are better handled as separate work.

Follow-ups

1. Expose PxRigidBodyExt::addForceAtPos in physX.js and route DynamicCollider.applyForceAtPosition through it.

   Reason: physX.js currently binds addForce / addTorque, while the addForceAtPos binding is present but commented out in ActorBinding.h. Engine-side torque calculation is correct today, but pushing this operation back to the PhysX extension reduces long-term maintenance risk around center-of-mass, coordinate-space, and scale semantics.

   Acceptance direction: expose the binding in physX.js, add/update engine-side adapter support, and keep the existing applyForceAtPosition behavior tests passing.

2. Add an offline/pre-cooked mesh collider path for static imported assets.

   Reason: runtime mesh cooking is useful for editor preview, hot updates, and dynamic/generated meshes. For production static collider meshes, PhysX recommends offline cooking and loading cooked streams to avoid runtime cooking cost and first-use stalls.

   Acceptance direction: imported/static model collider meshes can reuse cached cooked data, while runtime cooking remains available as a fallback for dynamic meshes.

3. Make PhysX scene/filter contact and CCD reporting configurable.

   Reason: the current physX.js default scene desc enables CCD, keeps kinematic/static filtering pairs, and the filter shader emits contact notifications, contact points, CCD contact detection, and CCD touch notifications by default. This is a useful engine default, but projects that do not need full contact reporting should be able to avoid that overhead.

   Acceptance direction: expose engine-level PhysX options for contact/CCD reporting policy without changing the current default behavior.

Non-goals

• This is not a blocker for fix(physics): gate contact event buffering #3025.
• This issue should not force all three items into one implementation PR; they can be split when scoped.
• Do not remove runtime cooking, since editor and dynamic mesh scenarios still need it.

[luzhuang]

Follow-up 1 is now split into implementation PRs:

• galacean/physX.js#19 exposes the PhysX rigid body at-position helpers in the binding.
• galacean/engine#3039 adds DynamicCollider.applyForceAtPosition(...), consumes the rebuilt wasm, and adds behavior coverage.

Keeping this tracker open for the remaining follow-ups: offline/pre-cooked mesh collider data and configurable PhysX scene/filter reporting policy.