Implement arParamChangeSize, ar3DCreateHandle, and arglCameraFrustumRH (+ audit related functions with code references)

[kalwalt]

Implement the following functions for WebARKitLib-rs, as outlined in the project plan (#1):

• arParamChangeSize (ParamChangeSize.c example)
• ar3DCreateHandle (Rust existing prototype)
• arglCameraFrustumRH (functionality not yet stubbed, but coordinate/projective code is present in core/math.rs and ar2.rs)

Reference implementations and notes

arParamChangeSize

• See: main.c: arParamChangeSize(&cparam, width, height, &cparam);
• Handles resizing camera parameters (projection matrix, etc.)
• Struct: ARParam

ar3DCreateHandle

• Partial Rust port: ar_3d_create_handle
• Relies on the AR3DHandle struct
• Typically used after camera param init

arglCameraFrustumRH

• Related code: no direct port, but see mathematical helpers and matrix projection math in math.rs and projecting functions in ar2.rs
• This function typically computes an OpenGL-style right-handed frustum matrix using calibration params

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Additional tasks

• Audit dependencies and suggest other required or closely-related functions (ex: those that rely on/extend arParamChangeSize, ar3DCreateHandle, or arglCameraFrustumRH)
• Suggest additional small functions to include if trivial or beneficial
• Document design and relevant types for future contributors

Useful Rust stubs or references

• ARHandle usage example
• ARParam struct definition
• AR3DHandle struct test

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Please attach code links or code blocks in PRs to clarify how functionality matches ARToolKit/ARToolKitX (C) implementations.