Make step and tool result contracts explicit

[chubes4]

Summary

• Wrap first-party Step::execute() output in the explicit StepExecutionResult contract before the engine routes it.
• Stop mirroring canonical AI tool result payloads back into data in Data Machine tool/runtime result paths.
• Update focused smokes and unit expectations around explicit step packets and result-first tool payloads.

Closes #2410.
Closes #2412.

Tests

• php tests/step-base-explicit-result-smoke.php && php tests/step-execution-result-contract-smoke.php && php tests/tool-executor-ability-native-smoke.php && php tests/tool-result-consumer-contract-smoke.php && php tests/ability-result-wp-error-smoke.php
• vendor/bin/phpcs inc/Core/Steps/Step.php inc/Core/AbilityResult.php inc/Engine/AI/Tools/Execution/ToolExecutionCore.php inc/Engine/AI/Tools/ToolResultFinder.php inc/Engine/AI/ConversationManager.php inc/Engine/AI/DataMachineCompletionAssertions.php inc/Engine/AI/conversation-loop.php tests/step-base-explicit-result-smoke.php tests/tool-executor-ability-native-smoke.php tests/tool-result-consumer-contract-smoke.php tests/ability-result-wp-error-smoke.php tests/Unit/Core/Steps/AI/AIStepTest.php tests/Unit/Core/Steps/Upsert/UpsertStepTest.php tests/Unit/Engine/AI/Tools/ToolResultFinderTest.php
• homeboy test --path "/Users/chubes/Developer/data-machine@fix-result-step-contracts-2410-2412" --changed-since HEAD~1 (1222 passed, 3 skipped)

AI assistance

• AI assistance: Yes
• Tool(s): OpenCode (GPT-5.5)
• Used for: Drafted the code changes, tests, and verification flow for Chris to review.

[homeboy-ci]

Homeboy Results — data-machine

Lint

❌ lint — failed

Deep dive: homeboy lint data-machine --changed-since 424a39a

Artifacts and drill-down

• CI results artifact: homeboy-ci-results-data-machine-lint-quality-Linux-node24 contains immediate command JSON for this action invocation.
• Observation artifact: homeboy-observations-data-machine-lint-quality-Linux-node24 contains exported Homeboy run history for deeper queries.
• Drill-down: download the observation artifact, then run homeboy runs import <dir>, homeboy runs list, and homeboy runs findings <run-id>.
• Artifacts are attached to the workflow run: https://github.com/Extra-Chill/data-machine/actions/runs/26714877756

Test

✅ test — passed

• 1222 passed
• 3 skipped

ℹ️ Auto-fix lint issues: homeboy refactor data-machine --from lint --write
ℹ️ Collect coverage: homeboy test data-machine --coverage
ℹ️ Save test baseline: homeboy test data-machine --baseline
ℹ️ Pass args to test runner: homeboy test -- [args]
ℹ️ Full options: homeboy docs commands/test
Deep dive: homeboy test data-machine --changed-since 424a39a

Artifacts and drill-down

• CI results artifact: homeboy-ci-results-data-machine-test-quality-Linux-node24 contains immediate command JSON for this action invocation.
• Observation artifact: homeboy-observations-data-machine-test-quality-Linux-node24 contains exported Homeboy run history for deeper queries.
• Drill-down: download the observation artifact, then run homeboy runs import <dir>, homeboy runs list, and homeboy runs findings <run-id>.
• Artifacts are attached to the workflow run: https://github.com/Extra-Chill/data-machine/actions/runs/26714877756

Audit

✅ audit — passed

• audit — 31 finding(s)
• Total: 31 finding(s)

Deep dive: homeboy audit data-machine --changed-since 424a39a

Artifacts and drill-down

• CI results artifact: homeboy-ci-results-data-machine-audit-quality-Linux-node24 contains immediate command JSON for this action invocation.
• Observation artifact: homeboy-observations-data-machine-audit-quality-Linux-node24 contains exported Homeboy run history for deeper queries.
• Drill-down: download the observation artifact, then run homeboy runs import <dir>, homeboy runs list, and homeboy runs findings <run-id>.
• Artifacts are attached to the workflow run: https://github.com/Extra-Chill/data-machine/actions/runs/26714877756

Tooling versions

• Homeboy CLI: homeboy 0.213.4+ed1c8288
• Extension: wordpress from https://github.com/Extra-Chill/homeboy-extensions
• Extension revision: 06cc67ae
• Action: unknown@unknown