feat(core): implement arParamChangeSize and arglCameraFrustumRH

[Copilot]

Summary

Closes / implements #19.

This PR ports three groups of ARToolKit C functions into Rust as part of the WebARKitLib-rs API build-out:

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1. arParamChangeSize → ar_param_change_size (crates/core/src/ar/param.rs)

• In-place mutation of an ARParam struct to a new output resolution.
• Scales all focal-length and principal-point fields (fx, fy, cx, cy) by the ratio of the new size to the original.
• C equivalent: arParamChangeSize in param.c.
• Returns Err(ArParamError) on zero-width/height inputs.
• Full unit-test coverage included.

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2. New module param_gl (crates/core/src/ar/param_gl.rs)

Ports four OpenGL matrix-generation helpers from ARToolKit's paramGL.c:

Rust function	C equivalent	Description
argl_camera_frustum_rh	arglCameraFrustumRH	f64 right-handed OpenGL frustum/projection matrix from ARParam
argl_camera_view_rh	arglCameraViewRH	f64 right-handed OpenGL model-view matrix from a 3×4 pose matrix
argl_camera_frustum_rh_f	arglCameraFrustumRHf	f32 variant of the frustum function
argl_camera_view_rh_f	arglCameraViewRHf	f32 variant of the model-view function

All functions return 16-element column-major arrays ready for use with glUniformMatrix4fv.
Full unit tests and doc-examples are included for each function.

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3. Module wiring (mod.rs, lib.rs)

• param_gl added to crates/core/src/ar/mod.rs (table entry + pub mod declaration).
• param_gl re-exported from crates/core/src/lib.rs.

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4. Bug fix — Clippy doc_overindented_list_items

• Fixed over-indented doc-comment continuation line in param_gl.rs:249 (12-space indent → 2-space indent) to resolve CI failure.

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Files changed

File	Change
crates/core/src/ar/param.rs	ar_param_change_size implementation + tests
crates/core/src/ar/param_gl.rs	New file — four paramGL.c functions, docs, tests
crates/core/src/ar/mod.rs	Register param_gl module
crates/core/src/lib.rs	Re-export param_gl