Mediate conversation tools through Agents API

[chubes4]

Summary

• Closes Migrate conversation tool execution to Agents API mediation #2453 by moving Data Machine conversation tool execution onto the Agents API mediated loop (tool_executor, tool_declarations, pre_tool_mediator, and canonical runtime-tool pending handling).
• Keeps Data Machine-specific policy at the mediation seam: duplicate rejection, runtime-rule rejection, client/runtime tool fulfillment, async pending requests, trace metadata, and provider-failure shaping.
• Preserves legacy chat/pipeline semantics while using upstream mediation: preflight policies evaluate prior transcript history, rejected preflight calls stay in canonical audit/transcript events but not DM's legacy tool result list, and completion assertions still see Data Machine result/parameter shapes.
• Updates the bundled Agents API dependency/package path from automattic/agents-api to wordpress/agents-api at the merged upstream commit that includes pre-tool mediation.

Upstream status

• Agents API mediation hooks needed for the normal server-tool slice have landed, so Agents API refactor: make handler_configs/handler_slugs single source of truth (#233) #259 is no longer blocking this PR's landing slice.
• External/client runtime tools remain mediated through Data Machine's existing pending/resume storage, surfaced through the canonical Agents API runtime_tool_pending envelope.

Verification

• php tests/agent-conversation-runtime-policy-smoke.php
• php tests/tool-executor-ability-native-smoke.php
• php tests/pending-actions-agents-api-contract-smoke.php
• php vendor/wordpress/agents-api/tests/conversation-loop-tool-execution-smoke.php
• vendor/bin/phpcs inc/Engine/AI/conversation-loop.php inc/Engine/AI/DataMachineHandlerCompletionPolicy.php inc/Engine/AI/DataMachineCompletionAssertions.php

AI assistance

• AI assistance: Yes
• Tool(s): OpenCode (openai/gpt-5.5)
• Used for: Implemented and tightened the mediated tool execution migration, preserved Data Machine compatibility seams, and ran smoke/lint verification. Chris remains responsible for review and testing.

[homeboy-ci]

Homeboy Results — data-machine

Lint

✅ lint — passed

ℹ️ Full options: homeboy docs commands/lint
Deep dive: homeboy lint data-machine --changed-since 53a97ac

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/26900687961

Test

✅ test — passed

• 1313 passed
• 4 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 53a97ac

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/26900687961

Audit

✅ audit — passed

• audit — 514 finding(s)
• Total: 514 finding(s)

Deep dive: homeboy audit data-machine --changed-since 53a97ac

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/26900687961

Tooling versions

• Homeboy CLI: homeboy 0.219.1+1eee2cef
• Extension: wordpress from https://github.com/Extra-Chill/homeboy-extensions
• Extension revision: 471a6b73
• Action: unknown@unknown