Support analyzer 14

## Request

Please bump the `analyzer` constraint to allow analyzer 14, following the prior release pattern:

```yaml
analyzer: '>=9.0.0 <15.0.0'
```

## Context

Latest published `source_helper` is `1.3.12` with:

```yaml
analyzer: '>=9.0.0 <14.0.0'
```

Downstream packages that need `analyzer: ^14.0.0` (for example `hive_ce_generator`) are blocked because `source_helper` does not allow analyzer 14 yet.

Previous bumps followed the same upper-bound pattern (`<11`, `<13`, `<14`). A `1.3.13` release with `'>=9.0.0 <15.0.0'` would unblock those dependents.

## Checklist

- [ ] Bump `analyzer` constraint to `'>=9.0.0 <15.0.0'`
- [ ] Bump package version (e.g. `1.3.13`) and update `CHANGELOG.md`
- [ ] Verify `dart analyze` / tests pass against analyzer 14

Start by locating the package manifest and the existing analyzer constraint, then compare it with the prior release pattern described in the issue. Update the constraint and package version, record the change in CHANGELOG.md, and run dart analyze and the test suite to verify analyzer 14 support.

Written by the indexing model from the issue text.