Extract run-composition logic from cli.py callbacks

[pbean]

Finding F-2 of the "Brownfield CLI/TUI Refactor Assessment" (local report, gitignored under _bmad-output/implementation-artifacts/).

Evidence

cli.py (2,588 lines) embeds workflow composition in argparse callbacks:

• cmd_run (cli.py:757-845) builds RunState, validates the worktree, and wires the Engine inline.
• _make_adapters (cli.py:125) and _platform_preflight (cli.py:214) are shared composition helpers living in the CLI module.
• cmd_sweep (cli.py:1056) and cmd_resume (cli.py:1229) repeat the pattern.

Run composition is untestable without argparse, and the TUI can only reuse it by argv round-trip.

Recommendation — two PRs

PR 1 (cmd_run): create src/bmad_loop/runsetup.py (single module — do NOT create a services/ package) holding the adapter factory, platform preflight, and RunState/Engine composition as typed functions; cmd_run becomes parse → call runsetup → render.

PR 2 (cmd_resume + cmd_sweep): extend the same pattern to the remaining logic-heavy callbacks. Scope guard (assessment anti-goals): do NOT touch thin render-only callbacks (status/list/decisions/attach/etc.) — that would be pass-through layering.

Ordering

Sessions 6-7 of the refactor program. PR 2 requires PR 1 merged (verify on main).

Traps

• The run subcommand's argv surface must not change — tui/launch.py round-trips through CLI argv; grep it for the flags it composes before touching anything.
• tests/test_cli.py monkeypatches cli.* names (e.g. cli._make_adapters) — keep those names importable from cli.py as re-exports/delegators so tests stay untouched and green.
• ruff F401 autofix deletes re-exports — pin with noqa: F401, verify with trunk check --no-fix.
• Behavior-preserving moves only; no CHANGELOG (not user-visible).

[coderabbitai]

🔗 Related PRs

#107 - refactor(restore): one latch validator, one path normalizer, one exclusion site [merged]
#110 - fix(runs): validate run ids and stop a run ref escaping the runs dir [merged]
#137 - feat(mux): herdr TUI-launch surface [merged]
#216 - refactor(documents): make the document builders public (#212) [merged]
#220 - feat: active agent indicator in TUI and status --json [merged]

---

📝 Issue Planner

_{Check the box below or use the @coderabbitai plan command to generate an implementation plan and prompts that you can use with your favorite coding assistant.}

• Create Plan

---

🧪 Issue enrichment is currently in open beta.

You can configure auto-planning by selecting labels in the issue_enrichment configuration.

To disable automatic issue enrichment, add the following to your .coderabbit.yaml:

issue_enrichment:
  auto_enrich:
    enabled: false

💬 Have feedback or questions? Drop into our discord!

[pbean]

Reopening: PR #262 completed PR 1 (cmd_run) and auto-closed this via a closing keyword, but the issue's plan calls for two PRs. PR 2 — extending the same runsetup composition seam to cmd_resume and cmd_sweep — is still outstanding and will close this.