chore: Update outdated third-party vendor libraries

[killerdevildog]

Description

Several vendored third-party libraries are significantly outdated. Updating them would bring bug fixes, performance improvements, better compiler support (especially for Linux/Clang), and security patches.

Version Comparison

Library	Current Version	Latest Version	Gap
Box2D	v2.4.1	v3.1.1	Major version behind
Dear ImGui	v1.89.2 WIP	v1.92.6	~3 minor versions behind
yaml-cpp	0.7.0	0.9.0	2 minor versions behind
spdlog	v1.11.0	v1.17.0	6 minor versions behind
EnTT	v3.11.0	v3.16.0	5 minor versions behind
JoltPhysics	~v2.x (2021 era)	v5.5.0	Multiple major versions behind
GLFW	Custom fork (MohitSethi99/glfw)	N/A	Fork-specific, missing Linux fixes (#33)

Notes

• Box2D v3.x is a major rewrite with a new C API — upgrading would require significant code changes to the 2D physics integration.
• JoltPhysics is vendored directly (not a submodule), making updates more involved. The current version is missing #include <cstdint> needed for Linux/Clang compilation.
• GLFW uses a custom fork with Hazel-specific features (titlebar control). Updating requires coordination with the fork maintainer.
• ImGui, spdlog, yaml-cpp, EnTT should be more straightforward to update as they tend to maintain backward compatibility across minor versions.

Suggested Priority

1. spdlog and EnTT — Low risk, high benefit (bug fixes, compiler compatibility)
2. Dear ImGui — Moderate risk, brings rendering improvements and bug fixes
3. yaml-cpp — Low risk, improved parsing and standards compliance
4. JoltPhysics — High effort, significant API changes between v2 and v5
5. Box2D — High effort, complete API rewrite in v3

Related

• Issue bug: GLFW X11/Wayland platform struct missing setWindowTitleBar function pointer #33 — GLFW fork missing X11/Wayland function pointer
• Issue feat: Linux platform support improvements #34 — Linux platform support improvements