CLI: Pipeline support for chaining multiple filters

[enzoftware]

Description

Add support for chaining multiple filters in a single CLI invocation, applying them sequentially to the input image.

Context

Users should be able to apply multiple transformations without writing intermediate files. For example:

silvestre apply grayscale gaussian --sigma 2.0 canny --input photo.jpg --output edges.jpg

Tasks

• Design pipeline syntax (multiple filter names with their params)
• Parse and validate the full pipeline before execution
• Apply filters sequentially, passing output of one as input to next
• Show progress for each step in the pipeline

Acceptance Criteria

• Multiple filters can be chained in a single command
• Filters are applied in the order specified
• Each filter's parameters are correctly associated with that filter
• Error in any pipeline step reports which step failed
• --help documents the pipeline syntax