chore(crop): Remove invalid crop area message and related validation logic

[balazs-szucs]

Description of Changes

On the crop UI, you cannot select outside the PDF. As this is the default behavior the validation and error is unnecessary on the FE. Also resolve a bug when you opened the PDF with the "default" crop area it showed out-of-bounds error.

No functional change expected

Changes:

• Removed out-of-bounds crop selection error alerts and parameter validation failures.
• Automatically clamp crop coordinates to the nearest page boundary (0 <= x <= actualWidth, 0 <= y <= actualHeight).
• Retained full PDF default page crop selection on initial open and reset.

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Checklist

General

• I have read the Contribution Guidelines
• I have read the Stirling-PDF Developer Guide (if applicable)
• I have read the How to add new languages to Stirling-PDF (if applicable)
• I have performed a self-review of my own code
• My changes generate no new warnings

Documentation

• I have updated relevant docs on Stirling-PDF's doc repo (if functionality has heavily changed)
• I have read the section Add New Translation Tags (for new translation tags only)

Translations (if applicable)

• I ran scripts/counter_translation.py

UI Changes (if applicable)

• Screenshots or videos demonstrating the UI changes are attached (e.g., as comments or direct attachments in the PR)

Testing (if applicable)

• I have run task check to verify linters, typechecks, and tests pass
• I have tested my changes locally. Refer to the Testing Guide for more details.

[Copilot]

Pull request overview

Removes the crop UI “out-of-bounds” validation/alert path (which could incorrectly trigger on initial open) and introduces a new “default” inset crop-area helper, while also deleting the now-unused crop.error.invalidArea translation key across locales.

Changes:

• Removed the crop-area validation alert from CropSettings and relaxed crop-area validity checks in the crop parameters hook.
• Added createDefaultCropArea (10% inset) and exposed resetToDefaultCropArea on the crop parameters hook.
• Removed crop.error.invalidArea from many locale TOMLs.

Reviewed changes

Copilot reviewed 45 out of 45 changed files in this pull request and generated 44 comments.

File	Description
frontend/editor/src/core/utils/cropCoordinates.ts	Adds a new helper to generate an inset “default” crop area.
frontend/editor/src/core/hooks/tools/crop/useCropParameters.ts	Adjusts crop-area validation and adds a new reset helper for the inset default.
frontend/editor/src/core/components/tools/crop/CropSettings.tsx	Removes the invalid-area alert from the crop UI.
frontend/editor/public/locales/*/translation.toml	Removes the crop.error.invalidArea key from en-US and many non-en-US locales.

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