Changes in version 0.2.0                        

  - ❗️ Renamed plan() to muttest_plan().
  - ✨ Add new mutators:
      - boolean_literal(), na_literal() — literal replacement mutators.
      - negate_condition(), remove_condition_negation() — condition
        mutators.
      - numeric_increment(), numeric_decrement(), index_increment(),
        index_decrement() — increment/decrement mutators.
      - string_empty(), string_fill() — string mutators.
      - call_name() — call name mutator.
      - remove_negation() — unary negation mutator.
      - replace_return_value() — return value mutator.
      - delete_statement() — removes assignments and standalone calls
        one at a time to catch untested side effects and dead
        assignments.
  - ✨ Add preset collections for all major mutator groups:
      - boolean_literals() — flips TRUE/FALSE and T/F.
      - na_literals() — swaps NA, NULL, and typed NA variants.
      - numeric_literals() — increments and decrements numeric
        constants.
      - index_mutations() — shifts subscript indices up and down by one.
      - string_literals() — empties non-empty strings and fills empty
        ones.
      - condition_mutations() — negates conditions and removes existing
        negations.
      - arithmetic_operators() — mutates arithmetic operators (+, -, *,
        /, ^, %%, %/%).
      - comparison_operators() — mutates comparison operators (<, >, <=,
        >=, ==, !=).
      - logical_operators() — mutates logical operators (&, |, &&, ||).
  - ✨ Mutators are now parametrized and accept configuration arguments.
  - ✨ ProgressMutationReporter now reports survived mutants.
  - ✨ Expose Mutator base class for building custom mutators.
  - ✨ muttest() supports parallel execution of mutants.
  - ✨ muttest() supports per-mutant timeouts to avoid hanging test runs.
  - 🥅 Improved error handling when test execution fails.

                 Changes in version 0.1.0 (2025-05-30)                  

  - ✨ Create a testing plan with plan.
  - ✨ Run mutation testing with muttest.
  - ✨ Support mutating operators with operator.
  - ✨ Control copying project to temporary directory with CopyStrategy:
      - PackageCopyStrategy implemented for copying package files.
  - ✨ Control test execution for each mutant with TestStrategy:
      - FullTestStrategy for running all tests for each mutant.
      - FileTestStrategy for running only test files matching mutant
        files.
  - ✨ See test results with MutationReporter.
      - ProgressMutationReporter for printing progress to the console.