feat: Add DataFrame support in dy.Collection

[gab23r]

Motivation

Closes #319

Changes

• Add is_lazy attribute in MemberInfo.
• Add lazy_members and eager_members to dy.Collection-
• Internals still works on lazyframes via the new _to_lazy_dict methods.
• Modify Collection._init to collect the dataframe is the eager case.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (b339296) to head (245f0f4).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##              main      #335   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           56        56           
  Lines         3404      3427   +23     
=========================================
+ Hits          3404      3427   +23     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[Copilot]

Pull request overview

Adds first-class support for eager dy.DataFrame[...] members in dy.Collection, enabling collections to expose Polars DataFrames directly (instead of always returning LazyFrames).

Changes:

• Extend member metadata with an is_lazy flag and add lazy_members() / eager_members() helpers.
• Introduce internal _to_lazy_dict() and switch internal operations (join/collect_all/storage/filter-result collection) to use it.
• Update collection initialization to eagerly .collect() members annotated as dy.DataFrame[...], plus add dedicated tests for eager/lazy/mixed collections.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
dataframely/collection/_base.py	Adds MemberInfo.is_lazy, derives eager vs lazy from annotations, introduces _to_lazy_dict(), and updates _init() to materialize eager members.
dataframely/collection/collection.py	Routes internal operations (join/collect_all/storage) through _to_lazy_dict() to support mixed eager/lazy collections.
dataframely/collection/filter_result.py	Ensures CollectionFilterResult.collect_all() operates on lazy views of members for mixed collections.
tests/collection/test_implementation.py	Updates annotation implementation tests to reflect dy.DataFrame[...] support.
tests/collection/test_dataframe_members.py	Adds new end-to-end tests for eager-only, lazy-only, mixed, and optional eager members.

[Oliver Borchert (borchero)]

Sorry it took so long to review this! Generally, I think that we can support this, I left a few comments to simplify the implementation a little

[Oliver Borchert (borchero)]

Thanks for the updates gab23r!