feat: add step.s3_upload pipeline step for S3-compatible object storage

[Copilot]

• Create module/pipeline_step_s3_upload.go with S3UploadStep implementation
• Create module/pipeline_step_s3_upload_test.go with tests
• Register step.s3_upload in plugins/pipelinesteps/plugin.go
• Update plugins/pipelinesteps/plugin_test.go to use dynamic step count (avoids hardcoded count breaking on merges)
• Add step.s3_upload to schema/schema.go coreModuleTypes (sorted)
• Add step.s3_upload schema entry to schema/module_schema.go

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[Copilot]

Pull request overview

This PR adds a new step.s3_upload pipeline step that enables uploading base64-encoded binary data from the pipeline context to AWS S3 or S3-compatible storage (MinIO, LocalStack). The implementation provides flexible configuration with template-based key generation, environment variable expansion for credentials, and support for both AWS and custom endpoints.

Changes:

• New S3 upload pipeline step with comprehensive base64 decoding support (standard, URL-safe, and raw variants)
• Template-based key resolution supporting dynamic values like {{ .user_id }} and {{ uuid }}
• Content type resolution from both static config and dynamic pipeline context
• 11 comprehensive unit tests covering all major functionality and edge cases
• Plugin registration and manifest updates
• Code formatting improvements (struct field alignment) across multiple files

Reviewed changes

Copilot reviewed 6 out of 36 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
module/pipeline_step_s3_upload.go	Core implementation of S3UploadStep with AWS SDK integration, template resolution, and base64 decoding
module/pipeline_step_s3_upload_test.go	Comprehensive test suite with 11 tests covering templating, content types, custom endpoints, and error cases
plugins/pipelinesteps/plugin.go	Registers step.s3_upload factory and adds it to the plugin manifest
plugins/pipelinesteps/plugin_test.go	Updates test expectations to account for the new step (28 → 29 factories)
Various module/*.go files	Standard gofmt struct field alignment improvements (cosmetic only)

[intel352]

@copilot apply changes based on the comments in this thread

Something to think about, there's already s3 storage functionality that exists in workflow, is your explicit addition of s3_upload an absolute necessity, or is it simply redundant of the existing functionaity?

[Copilot]

@copilot apply changes based on the comments in this thread

Something to think about, there's alre...

The existing S3Storage (s3_storage.go) is a modular module — it requires being declared in the config and started as a service. It provides PutObject(ctx, key, io.Reader) but has no content-type support, no base64 decoding, and no template key resolution.

step.s3_upload is a pipeline step that works inline in any pipeline config without a pre-registered module. It adds the pipeline-specific concerns: base64 decoding from context dot-paths, Go template key resolution ({{ uuid }}, {{ .user_id }}), and content_type/content_type_from resolution. They are complementary — S3Storage is the service-layer module while step.s3_upload is the pipeline-layer step.

Also fixed in e895ca6: added step.s3_upload to schema/schema.go coreModuleTypes and schema/module_schema.go which were missing from the initial commit.

[intel352]

@copilot tests are failing

[Copilot]

@copilot tests are failing

Fixed in 6b088e2. The merge from main brought in step.auth_validate and step.raw_response, making the hardcoded 29 in TestPluginLoads stale (actual count was 31). Updated the assertion to use len(p.StepFactories()) dynamically so it stays correct as more steps are added.