fix(catalogs): reject boolean priority in extension and preset catalog readers (#2589)

`bool` is a subclass of `int` in Python, so `int(True)` silently returns
`1`. The extension- and preset-catalog config readers coerced priority
with a bare `int(item.get("priority", idx + 1))`, which meant a YAML
config like:

    catalogs:
      - name: mine
        url: https://example.com/catalog.json
        priority: yes     # parses to True

was silently accepted as a valid priority of 1, quietly reordering the
catalog stack instead of raising the same `Invalid priority` error a
typo of `priority: not-a-number` already raises.

The sibling integration-catalog reader in `src/specify_cli/catalogs.py`
already guards this case (see `catalogs.py:137`). This change mirrors
that pattern in `extensions.py` and `presets.py` so the three catalog
validators stay consistent, and adds regression tests for both readers
matching the existing `test_load_catalog_config_rejects_boolean_priority`
template in `tests/integrations/test_integration_catalog.py`.