Harden binary-family searches against unsorted input

[Nullkernel]

Motivation

• Prevent incorrect results or undefined behavior when binary-family algorithms are run on unsorted arrays by enforcing a clear input contract.
• Align behavior across non-linear search implementations so callers see consistent semantics and messages instead of implicit mutations (e.g., implicit sorting).

Description

• Implemented a validation-and-reject policy in Binarysearch.java, Uniform_binarysearch.java, Interpolationsearch.java, and Fibonaccisearch.java to verify that input arrays are sorted and to return early with a clear message when they are not.
• Added an isSorted(int[]) helper to each updated class to perform the sortedness check.
• Updated user prompts to explicitly request array elements in non-decreasing (sorted) order and removed the implicit Arrays.sort(arr) from Fibonacci search so indices remain meaningful.
• Ensured scanners are closed on both early-return failure paths and normal exit paths.

Testing

• Ran compilation: javac Searching-algorithms/Binarysearch.java Searching-algorithms/Uniform_binarysearch.java Searching-algorithms/Interpolationsearch.java Searching-algorithms/Fibonaccisearch.java, which completed successfully.

---

Codex Task