Fix cleanup drain JSON run visibility

[chubes4]

Summary

• Emits the scheduled cleanup run JSON before --drain invokes Data Machine jobs so operators immediately get the run_id, job_id, and status/drain commands.
• Keeps the existing high-level workspace cleanup run --drain path and still emits the final verified drain/status JSON after draining completes.
• Extends the focused cleanup CLI smoke to prove the scheduled JSON exists before the parent drain command runs.

Fixes #689.

Verification

• php tests/smoke-worktree-cleanup-cli.php
• php tests/smoke-workspace-cleanup-run-context.php
• php tests/smoke-cleanup-run-storage.php
• php -l inc/Cli/Commands/WorkspaceCommand.php && php -l tests/smoke-worktree-cleanup-cli.php
• git diff --check
• composer validate --strict (reports existing package metadata warning: committed version field)

AI assistance

• AI assistance: Yes
• Tool(s): OpenCode (openai/gpt-5.5)
• Used for: Investigating the cleanup drain CLI path, drafting the minimal code/test change, and running local verification. Chris remains responsible for review and acceptance.