fix(docs): use system temp directory for --body-file to avoid rm denylist collision

[MScottAdams]

Problem

When agents use --body-file for PR/issue creation (per scm/github.md rules), they write a temp file to the worktree directory and then rm it afterward. The rm command is on Warp's default command denylist, so each cleanup triggers a user approval prompt -- blocking autonomous swarm agents.

Observed During

Swarm run 2026-04-09 -- all 3 agents blocked on rm <worktree>/pr-body.md approval, requiring manual intervention from the monitor user.

Proposed Fix

Change the --body-file convention in scm/github.md to write temp files to the system temp directory instead of the worktree. Files in the system temp directory are managed by the OS and do not require explicit rm calls.

• PowerShell: c:\temp (e.g. C:\Users\<user>\AppData\Local\Temp)
• Unix: /tmp or ``

Pattern:

1. Write PR body to [System.IO.Path]::GetTempFileName() (PS) or mktemp (Unix)
2. Pass the temp path to gh pr create --body-file <temp-path>
3. No explicit rm needed -- OS handles cleanup

This eliminates the denylist collision entirely without requiring users to modify their Warp agent permissions.

Files to Change

• scm/github.md -- update --body-file convention to use system temp directory
• skills/deft-swarm/SKILL.md -- note temp file convention in prompt template or launch guidance

[MScottAdams]

Roadmap Refresh Analysis (2026-04-09)

Category: Bug/Documentation -- scm/github.md convention correction

Summary: The --body-file convention in scm/github.md instructs agents to write temp files to the worktree directory and rm them afterward. rm is on Warp's default command denylist, so every cleanup triggers a user approval prompt -- directly blocking autonomous swarm agents. During the v0.15.0 swarm run, all 3 agents were blocked on rm <worktree>/pr-body.md. Fix: write to the OS temp directory so no explicit rm is needed.

Relationship to existing issues:

• Create scm/github.md — standing gh CLI rules, PR workflow conventions, and Windows encoding guidance #197 (completed, t2.6.6) -- created scm/github.md with the --body-file rule; this issue corrects the temp file location it implies
• bug(swarm): monitor skips Phase 5 (Review) and slam-merges untested code into main; conversation corrupts afterward #261 + chore(swarm): monitor crash during multi-PR merge — add checkpoint/recovery resilience #263 (Phase 1, t1.13.1) -- same swarm run; this was a contributing blockage alongside the Phase 5 skip

Scope: Small -- scm/github.md only: update --body-file convention to use [System.IO.Path]::GetTempFileName() / $env:TEMP on PS, mktemp on Unix. No explicit rm needed -- OS handles cleanup.

Recommendation: Phase 1 -- Adoption Blockers. Spec task t1.13.2. Small surface, clear fix, directly caused manual intervention during a swarm run.