Foundations 0.5.3

Tablet landscape now keeps the page outline visible on the right. The current section is highlighted as you read or work through its exercises, and tapping an entry jumps to that section. Portrait and narrow windows retain a compact outline menu.

Removed twelve redundant formula-and-text step-through figures, including all three in lesson one. The full worked explanations remain. The 39 retained figures show useful graph, set, mapping, counting, and growth structure.

Existing answers, handwriting, lesson identities, and reading anchors are preserved.