Create and run examples

I need runnable examples for the new physics API so engineers and students can learn quickly. Create three short example programs in examples/ that compile with the project build: one shows creating a rigid body and stepping simulation for 60 frames, one shows adding a joint between two bodies, and one demonstrates applying impulse on collision callback. Each example should print a minimal textual log of positions each frame and include build instructions in a README. Ladder L1

Before I publish these examples to the docs site, make them easy to copy into student projects: keep them single-file programs, show the exact compiler command to build them, use trivial printable output, and add a short note about which header(s) and libraries to link. Highlight any API calls that are unsafe for multi-threaded use. Ladder L2

I ran the rigid-body example and it behaves nondeterministically for students on different machines. They see diverging trajectories after a few frames. I suspect floating-point nondeterminism and unpinned threads. I can't reproduce it on my desktop because I run a debug build. What is the most probable cause and what change to the example will make behavior deterministic across machines for teaching? Ladder L5

Over time our examples either stop compiling or teach bad habits, and students waste time on trivial mismatches. What pattern of upkeep will prevent examples from becoming misleading, and what two habits should the team adopt when adding new examples so they remain correct and pedagogically useful? Ladder L6