Configure DMC promotion apply for Homeboy

[chubes4]

Summary

Configure Homeboy's DMC provider to discover the typed promotion apply adapter.

What changed

• Added exact promotion-apply argv generation with explicit {handle} substitution.
• Included commands.apply in setup/upgrade provider JSON.
• Hardened optional WP flag arrays and asserted the full provider contract.

How to test

1. Run bash tests/homeboy-dmc-provider.sh; expect exact provider contract and optional-skip paths pass.
2. Run bash -n lib/homeboy.sh tests/homeboy-dmc-provider.sh; expect shell syntax passes.

Compatibility

Additive provider field with preserved existing argv and safety mappings.

Evidence

Declared public contracts

• homeboy-dmc-provider-config: Generated DMC provider configuration now includes the typed promotion apply argv.

Compatibility impact: The apply command is additive; existing provider commands and mappings are unchanged. Empty optional WP flags no longer create empty argv values or set -u failures.

External-consumer impact: wp-coding-agents setup/upgrade will configure Homeboy to invoke the DMC adapter; users without the paired DMC/Homeboy versions retain existing commands but must not use apply until dependencies are present.

External usage: completed; source: Live Homeboy config output and wp-coding-agents provider generator tests; limitations: Full no-override Cook proof requires the paired Homeboy and DMC PRs to be built/installed together.; evidence: Extra-Chill/homeboy#7898

• Base unchanged since verification: main remains at d4b30d1.
• CI expected: GitHub Actions repository checks
• Reviewer-resolvable evidence from source_refs[0]: Configure DMC promotion apply command for Homeboy #291
• Reviewer-resolvable evidence from source_refs[1]: agent-task cook cannot promote into DMC-managed worktrees without an apply-capable provider command homeboy#7898
• Verified finalization base: main at d4b30d1
• empty-flags-portability: passed (no empty argv or set -u failure) (Passed)
• provider-contract: passed (exact apply, resolve, list, cleanup, enablement, and mapping JSON) (Passed)
• shell-syntax: passed (library and test scripts) (Passed)

AI assistance

• AI assistance: Yes
• Tool(s): Homeboy (OpenCode)
• Model: openai/gpt-5.6-terra
• Used for: Implemented the provider apply wiring and exact JSON assertions; GPT-5.6 Sol diagnosed the gate failure, hardened optional argv handling, added the regression assertion, and finalized the candidate.

Source relationships

• Closes Configure DMC promotion apply command for Homeboy #291
• Relates to agent-task cook cannot promote into DMC-managed worktrees without an apply-capable provider command homeboy#7898