Refine workspace agent routing guidance

[chubes4]

Summary

Make DMC generated guidance the concise authoritative workspace contract and stop embedding mutable workspace inventory state in every agent prompt.

What changed

• Move DMC to unique composition priority 20.
• Clarify that DMC owns authoritative repository/worktree state while Homeboy consumes managed worktrees for execution, gates, promotion, evidence, and publication.
• Add copyable routes for inspection, worktree creation/finalization, primary refresh, GitHub state, and local editing.
• Preserve primary freshness/read-only safety and policy filters.
• Remove workspace-inventory, its renderer/tests, and the obsolete workspace-change composition invalidation hook.
• Remove duplicated WordPress source-path policy now owned by wp-coding-agents.

No external consumer of datamachine_code_workspace_inventory_mode was found across the managed workspace; current inventory remains available through workspace list, workspace show, and workspace hygiene.

Verification

• php -l data-machine-code.php
• php -l inc/Runtime/AgentsMdSections.php
• php -l inc/Workspace/WorkspaceCoreUtilities.php
• php tests/smoke-agents-md-sections.php
• Integrated four-owner composition: 95 lines / 6,822 bytes, down from the current 212-line generated document.

Coordination

• Fixes Clarify DMC routing and remove snapshot inventory from AGENTS.md #949
• wp-coding-agents: Make generated WordPress and Homeboy guidance routing-oriented wp-coding-agents#298
• Data Machine: Replace the exhaustive AGENTS.md CLI map with default routing data-machine#2990
• Intelligence: Automattic/intelligence#897

Each sibling change uses a unique priority and remains safe to merge independently.

AI assistance

• Tool: OpenCode
• Model: OpenAI GPT-5.6 Sol
• Used for: Audited DMC section and inventory ownership, implemented the concise workspace contract and lifecycle cleanup, composed the integrated candidate, and reviewed the resulting flow with Chris.

[chubes4]

Coordinated AGENTS.md routing set: Extra-Chill/wp-coding-agents#299, Extra-Chill/data-machine#2991, #950, and Automattic/intelligence#898. The integrated candidate renders in deterministic priority order as WordPress reference → Abilities → Intelligence → Data Machine → DMC → Homeboy.