[Feature] File Metadata Enrichment

[RuslanPr0g]

Description
Enrich file objects passed through pipelines with additional metadata such as:

• File size
• Created/modified date
• MIME type (optional)

Acceptance Criteria

• IFileResource or similar abstraction includes metadata properties.
• Metadata available in all pipeline steps.
• Optional: configurable metadata enrichment.

Benefits

• Enables more advanced filtering, auditing, and processing logic.