docs(harness-adapters): remove incorrect single-worker-only claim from AGY docs

[marcusvpn1]

Intent

Remove the incorrect single-worker only claim from the AGY harness adapter docs. The captain confirmed directly that multiple concurrent AGY sessions work fine, and this claim had no cited test or verification evidence. Keep the other two EXPERIMENTAL caveats: no secondmate support and no verified turn-end hook. Only line 406 in .agents/skills/harness-adapters/SKILL.md needed changing.

What Changed

• Removed the "single-worker only" caveat from the AGY EXPERIMENTAL note in .agents/skills/harness-adapters/SKILL.md, since multiple concurrent AGY sessions are confirmed to work.
• Retained the other two EXPERIMENTAL caveats: no secondmate support and no verified turn-end hook.

Risk Assessment

✅ Low: Single-line documentation edit that removes exactly the claim specified in the intent while preserving the other two caveats; no code or behavior is affected.

Testing

This is a docs-only, single-line prose fix with no code path or automated test coverage over its content, so I verified it via direct diff inspection: the target commit removes only the phrase "single-worker only, " from line 406 of .agents/skills/harness-adapters/SKILL.md, leaving the "no secondmate support, and no verified turn-end hook" caveats untouched, matching the stated intent exactly, and no other files or lines were touched.

Evidence: SKILL.md AGY caveat line diff (base vs target)

-AGY is EXPERIMENTAL: single-worker only, no secondmate support, and no verified turn-end hook (busy/idle pane detection is the only completion signal). +AGY is EXPERIMENTAL: no secondmate support, and no verified turn-end hook (busy/idle pane detection is the only completion signal).

diff --git a/.agents/skills/harness-adapters/SKILL.md b/.agents/skills/harness-adapters/SKILL.md
index 8c95cb3..c408a2d 100644
--- a/.agents/skills/harness-adapters/SKILL.md
+++ b/.agents/skills/harness-adapters/SKILL.md
@@ -403,7 +403,7 @@ The guarded turn-end signal remains a wake notification; standalone Kimi has no
 
 ## agy (VERIFIED 2026-07-29, Antigravity CLI 1.1.8, Gemini 3.6 Flash)
 
-AGY is EXPERIMENTAL: single-worker only, no secondmate support, and no verified turn-end hook (busy/idle pane detection is the only completion signal).
+AGY is EXPERIMENTAL: no secondmate support, and no verified turn-end hook (busy/idle pane detection is the only completion signal).
 It launches bare into a real interactive TUI, the same shape as claude/codex/opencode/pi/grok/kimi, not a one-shot print mode.
 `bin/fm-busy-lib.sh` owns AGY task-state classification under the new lifecycle contract: its AGY-only fallback returns busy or idle only when the corresponding explicit pane signature below is present, and returns unknown for every inconclusive capture.
 `bin/fm-tmux-lib.sh` reuses the same busy signature for delivery and supervisor-input guards, but does not independently classify recorded AGY task state.

- Outcome: ⚠️ 1 info across 1 run (1m1s)

Pipeline

Updates from git push no-mistakes

✅ **intent** - passed

✅ No issues found.

✅ **Rebase** - passed

✅ No issues found.

✅ **Review** - passed

✅ No issues found.

⚠️ **Test** - 1 info

• ℹ️ bin/fm-agy-lib.sh:25 - Two code comments elsewhere in the repo still assert the same now-corrected 'single-worker only' claim for AGY: bin/fm-agy-lib.sh:25 and bin/fm-spawn.sh:78. The user intent explicitly scoped this change to only SKILL.md line 406, so this is out of scope for this change, but it leaves the codebase docs/comments inconsistent with the corrected SKILL.md claim.
• git diff 72920c46..dcd2eb30 -- .agents/skills/harness-adapters/SKILL.md — confirmed exactly one line changed at the AGY EXPERIMENTAL caveat, 'single-worker only, ' removed, both remaining caveats intact
• git diff --stat between base and target — confirmed only 1 file / 1 line changed overall
• grep for other 'single-worker' mentions inside .agents/skills/harness-adapters/ — none remain
• grep across tests/ for AGY/EXPERIMENTAL SKILL.md references — no automated test exercises this doc's prose, confirming manual diff inspection is the appropriate evidence
• grep across bin/ for stray 'single-worker' mentions — found two (bin/fm-agy-lib.sh:25, bin/fm-spawn.sh:78) still claiming single-worker only, outside the scoped file

✅ **Document** - passed

✅ No issues found.

✅ **Lint** - passed

✅ No issues found.

✅ **Push** - passed

✅ No issues found.