fix(wtsite): repair the dangling combine_into reference

[LukasGold]

Closes #15.

Changes

• _combine_into in src/osw/wtsite.py: the recursive dict merge that update_dict has always called and that never existed.
• WtPage.update_dict is now a staticmethod and delegates to it. It never used self.
• WtPage.set_value: dropped print(match.full_path) and called the merge helper directly.
• tests/test_wtpage_update_dict.py: 10 offline tests.

Rationale

update_dict called wt.combine_into, which does not exist anywhere in this repository and never has. It was written as WtPage.combine_into in the commit that introduced the class (5486996, October 2022) and was never defined, then later rewritten to wt.combine_into without being defined there either. Any nested dict therefore raised AttributeError.

Writing tests for the one caller, set_value, turned up two further defects on the same path:

• WtPage.update_dict(match.value, value) at the call site passed two arguments to a three-parameter instance method, so match.value bound to self and update was missing. TypeError before the missing reference was ever reached.
• print(match.full_path) raised TypeError: expected string or bytes-like object, got 'int'. set_value keys its working dict by list index, and jsonpath_ng regex-matches field names when it renders a path, so rendering an integer key fails. This one broke set_value on every call, replace=True included, which is why the other two were never observed.

All three are fixed here rather than filed separately, since they are one broken path and the tests that exposed them are in this PR.

Notes

• update_dict and set_value keep their @deprecated markers. This repairs them, it does not revive them.
• Making update_dict a staticmethod keeps the existing WtPage.update_dict(a, b) call shape working and does not break page.update_dict(a, b) either. The three-argument form was never functional.
• A dict merged onto a non-dict replaces it, and a fresh nested dict is copied rather than aliased into the merge target, so a later edit of the result cannot reach back into the argument.
• print(match.full_path) was debug output, so it is removed rather than converted to logging. A comment records why the path cannot be rendered, since that is not obvious. Converting the library's remaining 205 print calls is replace all print statements with proper logging #130.
• The deeper option the issue raises, reworking WtPage._dict for multi-slot pages, is untouched. That is a different change and these methods are deprecated.

Verification

Offline suite passes (64 passed, 1 skipped).

[github-actions]

Release preview

Merging this PR would release v2.0.3 (current: v2.0.2).

Changelog preview (truncated)

## v2.0.3 (2026-09-02)

### Bug Fixes

- **wtsite**: Repair the dangling combine_into reference
  ([`707be40`](https://github.com/OpenSemanticLab/osw-python/commit/707be4030e9221e8180de0198e4282b4d0cb4fcc))

### Testing

- Rename oold.py to oold_test.py so its tests are collected
  ([`20072a9`](https://github.com/OpenSemanticLab/osw-python/commit/20072a9249cd97126a222c62a70f84e0433343ef))

_{Preview via python-semantic-release and conventional commits.}

[LukasGold]

Fixed missing reference correctly