feat(handoff): claim_pings/review_pings accept a list — ping every reviewer

Multi-reviewer setups (e.g. a correctness + a readability adversary) can now have
the watchdog ping ALL reviewers on a claim, each in its own session with its own
submit key. A bare string still works (single agent). _ping_agents() helper.

README.md

@@ -267,6 +267,9 @@ phases = [
   subject matches `claim_pattern` / `review_pattern`, and watches the two `inboxes` files. When a
   claim lands it pings the `claim_pings` agent; a review pings `review_pings`; an inbox change
   pings the relevant side. This is how the Builder and Adversary coordinate purely through git.
+  `claim_pings` / `review_pings` may be a single agent name **or a list** — e.g.
+  `claim_pings = ["correctness-adversary", "readability-adversary"]` pings every reviewer on a claim
+  (each in its own session), for multi-reviewer setups.
 
 ---
 

agents.py

@@ -599,15 +599,22 @@ def _show_pushed(cfg, repo, path):
             return r.stdout
     return ""
 
+def _ping_agents(cfg, value, default, msg):
+    """Ping one or more agents. `value` is an agent name, a LIST of names, or falsy (→ default).
+    Each target is pinged in its own session with its own backend's submit key — so a handoff can
+    notify multiple reviewers (e.g. claim_pings = ["correctness-adversary", "readability-adversary"])."""
+    names = value if isinstance(value, list) else [value or default]
+    for name in names:
+        agent = cfg["agents"].get(name)
+        session = agent["session"] if agent and agent.get("session") else (cfg["session_prefix"] + str(name))
+        submit = backend_of(cfg, agent).get("submit_key", "Enter") if agent else "Enter"
+        ping_session(session, msg, submit_key=submit)
+
 def handoff_check(cfg):
     h = cfg["loop"].get("handoff")
     if not h:
         return
     repo = handoff_repo(cfg)
-    sub = lambda name: cfg["agents"].get(name, {}).get("session", cfg["session_prefix"] + name)
-    builder_name = h.get("review_pings", "builder")
-    submit = (backend_of(cfg, cfg["agents"][builder_name]).get("submit_key", "Enter")
-              if builder_name in cfg["agents"] else "Enter")
     claim_pat = h.get("claim_pattern", "^claim")
     review_pat = h.get("review_pattern", "^review")
     _git(repo, "fetch -q origin")
@@ -618,15 +625,15 @@ def handoff_check(cfg):
         elif head != _hand["sha"]:
             subjects = _git(repo, f"log --format=%s {_hand['sha']}..origin/main").stdout
             if re.search(claim_pat, subjects, re.M | re.I):
-                log("handoff: claim commit → pinging reviewer")
+                log("handoff: claim commit → pinging reviewer(s)")
-                ping_session(sub(h.get("claim_pings", "adversary")),
+                _ping_agents(cfg, h.get("claim_pings", "adversary"), "adversary",
                     "watchdog ping: the other loop pushed a gate CLAIM commit. "
-                    "Pull and verify the claimed gate now.", submit_key=submit)
+                    "Pull and verify the claimed gate now.")
             if re.search(review_pat, subjects, re.M | re.I):
                 log("handoff: review commit → pinging builder")
-                ping_session(sub(h.get("review_pings", "builder")),
+                _ping_agents(cfg, h.get("review_pings", "builder"), "builder",
                     "watchdog ping: the other loop pushed a verdict/finding commit. "
-                    "Pull the review file and act.", submit_key=submit)
+                    "Pull the review file and act.")
             _hand["sha"] = head
     inboxes = h.get("inboxes", [])
     md5 = lambda s: hashlib.md5(s.encode()).hexdigest()
@@ -642,9 +649,9 @@ def handoff_check(cfg):
             hh = md5(content)
             if hh != _hand[key]:
                 log(f"handoff: {fname} changed → pinging {target}")
-                ping_session(sub(target),
+                _ping_agents(cfg, target, target,
                     f"watchdog ping: the other loop pushed {sub_dir}/{fname} — pull, read it, "
-                    f"act, then delete the file (commit + push) to mark it consumed.", submit_key=submit)
+                    f"act, then delete the file (commit + push) to mark it consumed.")
                 _hand[key] = hh
         else:
             _hand[key] = ""