fix(core): downscale oversized images

[bugkeep]

Fixes #7791.

Problem

• compress_image() only triggered when the source file was larger than 1MB, so a dimension-oversized but highly-compressible image (e.g. solid-color PNG) could bypass downscaling and then be rejected by upstream vision limits (2048x2048).

Change

• When the source is below the size threshold, probe image dimensions and still downscale if max(width, height) > max_size.
• Applies to both local paths and data:image/... payloads.

Tests

• uv run pytest -q tests/unit/test_media_utils_compress_image.py
• uv run ruff format .
• uv run ruff check .

Summary by Sourcery

Ensure oversized images are downscaled even when their file size is below the compression threshold.

Bug Fixes:

• Prevent large-dimension but small-file-size images from bypassing downscaling and being rejected by upstream vision size limits.

Tests:

• Add unit tests covering downscaling of small-file local images, skipping compression for small images within size limits, and handling of oversized data URL images.

[sourcery-ai]

Hey - I've left some high level feedback:

• The _exceeds_max_size_bytes and _exceeds_max_size_path helpers duplicate the same logic; consider consolidating them into a single helper that accepts a file-like object or a more generic input to reduce repetition.
• Both helpers swallow all exceptions and return False, which could silently mask real image parsing errors; it may be safer to either log these failures or narrow the exception types so unexpected issues surface.

Prompt for AI Agents

Please address the comments from this code review:

## Overall Comments
- The `_exceeds_max_size_bytes` and `_exceeds_max_size_path` helpers duplicate the same logic; consider consolidating them into a single helper that accepts a file-like object or a more generic input to reduce repetition.
- Both helpers swallow all exceptions and return `False`, which could silently mask real image parsing errors; it may be safer to either log these failures or narrow the exception types so unexpected issues surface.

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[gemini-code-assist]

Code Review

This pull request enhances the image compression logic to account for image dimensions, ensuring that images exceeding a specified size are compressed even if their file size is small. It also introduces unit tests to verify these changes. The review feedback recommends refactoring the two new helper functions into a single, more versatile helper to eliminate code duplication.

[gemini-code-assist]

The two helper functions _exceeds_max_size_bytes and _exceeds_max_size_path perform nearly identical logic. Per the general rules, these should be refactored into a single shared helper function to avoid code duplication. Since PILImage.open accepts both file-like objects and path-like objects, a single helper can handle both cases. Additionally, ensure that this new attachment handling logic is accompanied by corresponding unit tests.

Suggested change

	def _exceeds_max_size_bytes(raw: bytes) -> bool:
	try:
	with PILImage.open(io.BytesIO(raw)) as opened_img:
	return max(opened_img.size) > max_size
	except Exception: # noqa: BLE001
	return False
	def _exceeds_max_size_path(path: Path) -> bool:
	try:
	with PILImage.open(path) as opened_img:
	return max(opened_img.size) > max_size
	except Exception: # noqa: BLE001
	return False
	def _exceeds_max_size(source: bytes | Path) -> bool:
	try:
	fp = io.BytesIO(source) if isinstance(source, bytes) else source
	with PILImage.open(fp) as opened_img:
	return max(opened_img.size) > max_size
	except Exception: # noqa: BLE001
	return False

References

1. When implementing similar functionality for different cases (e.g., direct vs. quoted attachments), refactor the logic into a shared helper function to avoid code duplication.
2. New functionality, such as handling attachments, should be accompanied by corresponding unit tests.

[gemini-code-assist]

Update the call to use the refactored helper function.

Suggested change

	if len(data) < min_file_size_bytes and not _exceeds_max_size_bytes(data):
	if len(data) < min_file_size_bytes and not _exceeds_max_size(data):

References

1. When implementing similar functionality for different cases (e.g., direct vs. quoted attachments), refactor the logic into a shared helper function to avoid code duplication.

[gemini-code-assist]

Update the call to use the refactored helper function.

Suggested change

	and not _exceeds_max_size_path(local_path)
	and not _exceeds_max_size(local_path)

References

1. When implementing similar functionality for different cases (e.g., direct vs. quoted attachments), refactor the logic into a shared helper function to avoid code duplication.