fix: register code abilities during API hook replay

[chubes4]

Summary

• Register DMC abilities only while wp_abilities_api_init is running, otherwise defer to the next hook run.
• Retry DMC bootstrap on later runtime hooks when Data Machine core becomes available after DMC is first loaded.
• Update smoke coverage for hook-time and deferred Abilities API registration.

Verification

• php tests/smoke-late-ability-registration.php
• php tests/smoke-deferred-ability-registration.php
• php -l data-machine-code.php && php -l inc/Abilities/WorkspaceAbilities.php && php -l inc/Abilities/GitHubAbilities.php && php -l inc/Abilities/GitSyncAbilities.php && php -l inc/Abilities/WordPressRuntimeAbilities.php && php -l inc/Abilities/CodeTaskAbilities.php && php -l inc/Abilities/WorkspaceDiffAbilities.php && php -l tests/smoke-deferred-ability-registration.php
• Local wp-codebox probe confirmed datamachine/workspace-show and datamachine/workspace-worktree-add resolve inside agent-sandbox-run.

AI assistance

• AI assistance: Yes
• Tool(s): OpenCode (gpt-5.5)
• Used for: Diagnosed the Abilities API hook replay behavior, drafted the bootstrap/registration fix and smoke updates, and ran local verification. Chris remains responsible for review and merge.