feat: Add step.base64_decode pipeline step

[Copilot]

• Create module/pipeline_step_base64_decode.go with Base64DecodeStep implementation
• Create module/pipeline_step_base64_decode_test.go with 19 unit tests
• Register step.base64_decode in plugins/pipelinesteps/plugin.go
• Add schema definition in schema/module_schema.go
• Add to registered types list in schema/schema.go (sorted correctly)
• Add to type registry in cmd/wfctl/type_registry.go
• Build passes, all tests pass, linter clean
• Missing/invalid input_from path returns valid: false (not error)
• Non-string input returns valid: false (not error)
• invalid() returns all output keys with zero defaults
• Pre-decode size estimation prevents large allocations when max_size_bytes is set
• Tests updated to match non-fatal semantics; added tests for non-string input and complete key presence
• Fixed TestKnownModuleTypes_Sorted — step.base64_decode now in correct sorted position in schema/schema.go
• Fixed TestStepFactories and TestPluginLoads — updated expected counts to include step.base64_decode

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[Copilot]

Pull request overview

Adds a new built-in pipeline step type (step.base64_decode) to decode base64 payloads (raw base64 or data-URI), optionally validate MIME type and decoded size, and expose decoded metadata back to the pipeline context.

Changes:

• Implements Base64DecodeStep with config parsing, decoding, MIME detection, and optional validations.
• Registers the new step type across plugin manifest/factory wiring, schema registries, and wfctl’s type registry.
• Adds a dedicated unit test suite for the new step and helper functions.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
schema/schema.go	Adds step.base64_decode to the engine’s known built-in module type list.
schema/module_schema.go	Defines the module schema for step.base64_decode (config fields, inputs/outputs).
plugins/pipelinesteps/plugin.go	Registers the step in the pipeline-steps plugin manifest and factory map.
module/pipeline_step_base64_decode.go	New step implementation (decode + validate + output metadata).
module/pipeline_step_base64_decode_test.go	New unit tests covering formats, validation, and dotted-path resolution.
cmd/wfctl/type_registry.go	Adds the new step type to wfctl’s known step registry and config keys list.

[intel352]

@copilot apply changes based on the comments in this thread

Also fix the failing tests.

[intel352]

@copilot tests are failing

[Copilot]

@copilot tests are failing

Fixed in 7a99283. Two issues were causing failures after the main branch merge:

1. step.base64_decode was inserted out of order in coreModuleTypes in schema/schema.go — moved to its correct sorted position (after step.artifact_push)
2. TestStepFactories and TestPluginLoads in plugins/pipelinesteps had stale hardcoded counts that didn't account for step.base64_decode — updated to the correct values