feat: enhance Gradio interfaces for cubic, polynomial, quadratic, and simultaneous equation solvers with detailed descriptions and examples

feat: add Gradio interface for simultaneous equation solving; update equations tab to include new solver

feat: add Gradio interfaces for cubic and polynomial equation solving; update quadratic solver to use numpy

feat: add Gradio interfaces for trigonometric functions and remove old trigonometry interface

feat: implement Gradio interfaces for quadratic equation solving and visualization; remove old interfaces

refactor: remove unused algebra and arithmetic interfaces; add GCD, LCM, and prime check implementations

modularized app.py

refactor: reorganize algebra interfaces and remove unused quadratic solver