Add regression test for read_file GeoDataFrame return type (#1186)

[vickysharma-prog]

Description

Adds a regression test for #1186 to ensure read_file() returns a proper GeoDataFrame when passed a pandas DataFrame with an existing geometry column.

Background

Issue #1186 reported that read_file() was returning a pandas DataFrame with shapely geometry column instead of a proper GeoDataFrame. This prevented use of GeoDataFrame methods like .intersects() required by preprocess.split_raster.

The bug was fixed by @bw4sz in commit 6f0aca1 (Refactor read_file - #1042). The refactor introduced DeepForest_DataFrame which properly inherits from GeoDataFrame. However, the specific regression test requested in #1186 was not added.

This PR adds that test to prevent future regressions.

Test Coverage

Test Case 1: DataFrame with WKT string geometry -> Verifies GeoDataFrame + GeoSeries
Test Case 2: DataFrame with shapely geometry objects -> Verifies GeoDataFrame + GeoSeries

Assertions:

• isinstance(result, gpd.GeoDataFrame)
• isinstance(result.geometry, gpd.GeoSeries)
• geometry column exists
• All geometries are Polygons

Related Issue(s)

Closes #1186

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  AI tools used for initial research and understanding the codebase better. All code was written and verified manually.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 87.34%. Comparing base (ecf3a1c) to head (810be7e).
⚠️ Report is 7 commits behind head on main.

Additional details and impacted files

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  Coverage   87.34%   87.34%           
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  Files          24       24           
  Lines        2978     2978           
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  Hits         2601     2601           
  Misses        377      377           

Flag	Coverage Δ
unittests	87.34% <ø> (ø)

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[henrykironde]

I will leave this to Ben to have a look

[henrykironde]

you probably want to move this statement

assert 'geometry' in result_wkt.columns

above

assert isinstance(result_wkt.geometry, gpd.GeoSeries)

[vickysharma-prog]

Thanks @henrykironde @bw4sz ! Fixed the assertion order in both test cases.

[vickysharma-prog]

@bw4sz Hi! Just a gentle follow-up I've addressed Henry's feedback on the assertion order. All CI checks are passing.
Let me know if you'd like any further changes!