[NoelStephensUnity]

Purpose of this PR

Adds the job-safe math NetworkTransform needs and the allocator for compact transform handles. Nothing calls either yet, so behaviour is unchanged.

Stack (replaces #4123, review in order): #4231 math and handles → #4232 static delta check → #4233 native interpolator and sync mode setting → #4234 blittable state and reliability → #4235 batched send path. Each PR targets the branch of the one before it; the diff shown is that PR alone.

PR Scope:

• NetworkTransformMath: Burst-compatible replacements for the engine math NetworkTransform uses (Euler conversion, delta angle, lerp and smooth dampening).
• QuaternionCompressor and HalfVector3: static, job-safe forms of the existing encode and decode paths. The existing public methods call them, so their output is unchanged.
• TransformHandleAllocator: hands out a ushort handle per NetworkTransform and holds released handles for a few seconds before reuse.

Out of scope:

• Everything that uses these (refactor: NetworkTransform delta detection as static job-safe methods (batched transforms 2/5) #4232-feat: batched NetworkTransform synchronization, one message per tick (batched transforms 5/5) #4235).

Jira ticket

N/A

Documentation

• No documentation changes or additions were necessary (internal API only).

Testing & QA (How your changes can be verified during release Playtest)

• NetworkTransformMathTests checks the job-safe math against the engine math.
• TransformHandleAllocatorTests covers allocation, release, hold and reuse.

Functional Testing

Manual testing :

• Manual testing done

Automated tests:

• Covered by existing automated tests
• Covered by new automated tests

Does the change require QA team to:

• Review automated tests?
• Execute manual tests?
• Provide feedback about the PR?

Up-port

N/A (develop-3.x.x only).

Backports

No backport is required.