emoji_eventsCalculator: evaluate an expression

Write evaluate(expr) that computes an arithmetic expression given as text, without eval, exec or ast.literal_eval.

• Numbers can be integers or decimals (3, 2.5).
• Operators + - * / with normal precedence, and parentheses.
• Unary minus: -3, 2 * -(1 + 1).
• Spaces may appear anywhere.
• Raise ValueError for invalid input ("2 +", "(1", "4 $ 2") and ZeroDivisionError for division by zero.

Acceptance criteria

• Return a float.
• The tests at the bottom print All tests passed.

Hint: a tokenizer plus a recursive-descent parser (expression → term → factor) keeps this short.