Add GPU Lesson 52 — PBR Textures (#509)

Add Physics Lesson 21 — Convex Hull Collision (#508)

Add PBR material assets and pipeline material plugin (#507)

Add GPU Lesson 51 — PBR Shading Model (#504)

Add Physics Lesson 20 — Compound Shapes (#503)

Add GPU Lesson 50 — Grass Rendering (#502)

Add Physics Lesson 19 — Kinematic Bodies (#500)

Add GPU Lesson 49 — Imposters (#501)

Add GPU Lesson 48 — Height Map Terrain (#495)

Fix L18 physics bugs and quit event handling in L16-L18 (#499)

Recapture L18 screenshot and GIF after title clip fix (#498)

Fix window and panel title text overflowing bounds (#497)

Improve ragdoll anatomy, joint variety, and visualization (#494)

feat(physics): add joint limits and motors (Lesson 18) (#492)

Add Asset Lesson 21 — Noise Texture Generation (#491)