fix(init): reverse default resolution when using manim init project --default

[aoxiangtianyu-go]

Overview: What does this pull request change?

This PR fixes a resolution inconsistency between the --default project initialization path and the interactive resolution selection flow.

The current CFG_DEFAULTS defines:

"resolution": (1920, 1080)

which is interpreted as (pixel_height, pixel_width) in the configuration system, resulting in an inverted default resolution compared to the interactive 1080p selection path and QUALITIES definitions.

It is updated to:

"resolution": (1080, 1920)

to align the --default initialization behavior with the rest of the CLI resolution pipeline.

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Motivation and Explanation: Why and how do your changes improve the library?

There is an inconsistency in how resolution tuples are represented during initialization:

• select_resolution() returns (pixel_height, pixel_width)
• QUALITIES defines resolution explicitly using pixel_height and pixel_width
• update_cfg() interprets resolution tuples as (height, width)

However, CFG_DEFAULTS previously defined resolution as (1920, 1080), which is inconsistent with this convention and leads to inverted default behavior when using manim init --default.

This reduces ambiguity and prevents unexpected inversion of width/height when using default project initialization.

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Links to added or changed documentation pages

No documentation changes are required for this fix.

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Further Information and Comments

There are broader architectural inconsistencies in how resolution is represented across the initialization pipeline (tuple-based vs explicit pixel_height/pixel_width fields).

This change is intentionally minimal and scoped only to correcting the default initialization value.

[chopan050]

LGTM! Thanks for this fix!