Fix image_compare expand output bug

[marthacryan]

Fixes #10902. The "Expand Output" button wasn't doing anything for the output of the following code snippet:

import marimo as mo
import numpy as np

# image as numpy array (shown in example figures)
mo.image_compare(
    before_image= np.random.random((1000, 700)),
    after_image = np.random.random((1000, 700)),
    value=0,
    # direction="horizontal",
    direction="vertical",
)

It's unclear why the original line of code was written but I tested this change and it fixed the bug that was reported.

[github-actions]

Thank you for your submission, we really appreciate it. Like many open-source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution. You can sign the CLA by just posting a Pull Request Comment same as the below format.

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I have read the CLA Document and I hereby sign the CLA

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[Copilot]

🟢 Approval recommended

The focused implementation directly addresses the reported bug and includes regression coverage.

Pull request overview

Fixes vertical image_compare outputs being fixed at 400px, allowing them to expand naturally.

Changes:

• Uses auto height when no explicit height is provided.
• Adds regression coverage for horizontal and vertical directions.

File summaries

File	Description
ImageComparisonComponent.tsx	Removes the vertical fixed-height default.
ImageComparisonComponent.test.tsx	Tests automatic container sizing.

Review details

• Files reviewed: 2/2 changed files
• Comments generated: 0
• Review effort level: Lite

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[cubic-dev-ai]

No issues found across 2 files

_{Re-trigger cubic}

[dmadisetti]

Huh, yeah

[akshayka]

@marthacryan , can you:

1. Sign the CLA by responding in a comment with only the following text:

I have read the CLA Document and I hereby sign the CLA

2. Add a PR label so the pull request labeling workflow passes?

[github-actions]

Coverage Report for ./frontend

Status	Category	Percentage	Covered / Total
🔵	Lines	58.69%	22505 / 38343
🔵	Statements	58.62%	22901 / 39062
🔵	Functions	51.83%	5086 / 9812
🔵	Branches	52.42%	11924 / 22745

File Coverage

File	Stmts	Branches	Functions	Lines	Uncovered Lines
Changed Files
frontend/src/plugins/impl/image-comparison/ImageComparisonComponent.tsx	100%	94.44%	100%	100%

Generated in workflow #21608 for commit b03822e by the Vitest Coverage Report Action

[kelreeeeey]

Thankyou kings/queens!!! <3