Autoloop: collapse program/steering/experiment-log into a single issue per program

[Copilot]

Each autoloop program currently fans out across three issues (program, steering, monthly experiment log), fragmenting activity and leaving the program issue silent while humans read and expect to steer there. This change collapses all three into the single autoloop-program-labeled issue.

Changes to .github/workflows/autoloop.md

• Pre-step (Python): partitions autoloop-program-labeled issues into (a) file-based program issues matched by title [Autoloop: {name}] against known file-based program names, exposed via selected_issue, and (b) issue-based programs (existing behavior). File-based programs now get the same single-issue treatment as issue-based ones.
• Unified "Program Issue" section replaces the separate "Experiment Log Issue" and "Steering Issue" sections. Documents: auto-creation on first run for file-based programs (title [Autoloop: {name}], labels autoloop-program, automation, autoloop, body mirrored from the program file), the in-place status comment (<!-- AUTOLOOP:STATUS --> sentinel, unchanged pattern), a new per-iteration comment for every outcome, and plain-prose human comments as steering input.
• Step 5 (Accept / Reject / Error): each branch now updates the single program issue instead of targeting separate experiment-log / steering issues. Drops monthly rollover and continuation-issue logic.
• Cross-Linking, Halting Condition, PR body template: reference the single program issue (#{selected_issue}). Completion label swap (autoloop-program → autoloop-completed) and celebratory comment now post to the program issue for all programs.
• State-file template + field reference: Steering Issue row replaced by a single Issue row.

Migration notes (out of scope, to be handled manually per the issue)

• perf-comparison (file-based): program issue auto-created on its next run.
• #1 (issue-based): remains the program issue; #107 and #130 can be closed and optionally archived into a pinned comment on #1.

Example — new per-iteration comment on the program issue

🤖 **Iteration 42** — [✅ Accepted](https://github.com/owner/repo/actions/runs/123)

- **Change**: switch inner loop to typed array
- **Metric**: 0.873 (best: 0.873, delta: +0.021)
- **Commit**: a1b2c3d
- **PR**: #57
- **Result**: typed arrays dominate; continue eliminating boxed numerics.

Only .github/workflows/autoloop.md is touched; no TS sources or tests are affected. The generated autoloop.lock.yml will be regenerated by gh-aw and is intentionally not edited by hand.