Use relative imports and document BoolValidator

Convert absolute imports to relative in validator modules to avoid
package import issues.

Add BoolValidator usage/docs and include a combined pytest command
to run validator-focused tests.

Author: daniel-crombie

ilovepdf/validators/README.md

@@ -64,6 +64,21 @@ IntValidator.validate_options(90, {0, 90, 180, 270}, "rotation")  # OK
 IntValidator.validate_options(45, {0, 90, 180, 270}, "rotation")  # Raises IntNotInAllowedSetError
 ```
 
+### BoolValidator
+
+Validates that a value is strictly a boolean (`True` or `False`).
+
+**Methods:**
+- `validate(value, param_name)` - Ensure the value is a boolean; raises a `TypeError` if not.
+
+**Example:**
+```python
+from ilovepdf.validators import BoolValidator
+
+BoolValidator.validate(True, "flatten")  # OK
+BoolValidator.validate("true", "flatten")  # Raises TypeError
+```
+
 ### FloatValidator
 
 Validates float values with various constraints.
@@ -231,6 +246,11 @@ pytest tests/unit/test_bool_validator.py -v
 pytest tests/unit/test_choice_validator.py -v
 ```
 
+To execute the validator-focused suite (including `BoolValidator`) in a single command:
+```bash
+pytest tests/unit/test_string_validator.py tests/unit/test_int_validator.py tests/unit/test_bool_validator.py tests/unit/test_choice_validator.py -v
+```
+
 ## See Also
 
 - `ilovepdf/abstract_task_element.py` - AbstractTaskElement base class

ilovepdf/validators/bool_validator.py

@@ -3,7 +3,7 @@
 Provides the BoolValidator class to validate boolean inputs for tasks and models.
 """
 
-from ilovepdf.exceptions import InvalidChoiceError
+from ..exceptions import InvalidChoiceError
 
 
 class BoolValidator:

ilovepdf/validators/choice_validator.py

@@ -7,7 +7,7 @@
 from collections.abc import Iterable
 from typing import Any
 
-from ilovepdf.exceptions import InvalidChoiceError
+from ..exceptions import InvalidChoiceError
 
 
 class ChoiceValidator:

ilovepdf/validators/float_validator.py

@@ -6,7 +6,7 @@
 
 from typing import Any
 
-from ilovepdf.exceptions import FloatOutOfRangeError, InvalidChoiceError
+from ..exceptions import FloatOutOfRangeError, InvalidChoiceError
 
 
 class FloatValidator:

ilovepdf/validators/int_validator.py

@@ -6,12 +6,12 @@
 
 from typing import Any
 
-from ilovepdf.exceptions import (
+from ..exceptions import (
     IntNotInAllowedSetError,
     IntOutOfRangeError,
     NotAnIntError,
 )
-from ilovepdf.validators.choice_validator import ChoiceValidator
+from . import ChoiceValidator
 
 
 class IntValidator: