Upgrade and Minor Fixes

[1.4.0] - 2026-06-02

Added

• Direct calculus commands: differentiate, integrate, simplify, and solve.
• Statistics toolkit with median, mode, range, variance, standard deviation, and summary.
• Geometry helpers for circle area, rectangle area, triangle area, hypotenuse, and 2D distance.
• Matrix toolkit with add, subtract, multiply, transpose, determinant, inverse, parsing, and formatting.
• SDK exports, TypeScript definitions, CLI help text, and tests for the new feature areas.

Improved

• Added npm install speed defaults via .npmrc (prefer-offline, no audit/fund, no progress).
• Cleaned package lock metadata for the current release version.