rofl: Split stdout and stderr for CLI commands

[ptrus]

Fixes #84

[Copilot]

Pull Request Overview

This PR separates stdout and stderr output streams for CLI commands instead of combining them into a single logs field. The change improves observability by allowing consumers to distinguish between standard output and error output from command executions.

• Split the single Logs field into separate Stdout and Stderr fields in command result structures
• Update all references to use the new separate fields in logging statements and result processing
• Modify command execution to capture stdout and stderr separately instead of combining them

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
worker/oasiscli/oasiscli.go	Updated command execution to capture stdout/stderr separately and modified result structure
worker/worker.go	Updated all log statements and result assignments to use separate stdout/stderr fields
tasks/roflbuild.go	Changed result structure to include separate stdout/stderr fields instead of logs
tasks/roflvalidate.go	Changed result structure to include separate stdout/stderr fields instead of logs
e2e/e2e_test.go	Updated test assertions to check stdout/stderr fields instead of logs

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