fix(agent-channel): preserve unaddressed continuation paragraphs in single-recipient messages

plugins/orchestrator/dist/server.js

@@ -24309,13 +24309,18 @@ class AgentChannel {
 }
 function filterParagraphsForReceiver(content, receiverId, sender, sessions) {
   const paragraphs = content.split(/\n{2,}/);
+  const paraAddrs = paragraphs.map((para) => parseAddressing(para, sender, sessions));
+  const targetSets = paraAddrs.filter((a) => a.targets.length > 0).map((a) => [...a.targets].sort().join(","));
+  const allAddressedParagraphsShareOneTargetSet = targetSets.length > 0 && targetSets.every((s) => s === targetSets[0]);
+  if (allAddressedParagraphsShareOneTargetSet) {
+    return paraAddrs.some((a) => a.targets.includes(receiverId)) ? content : null;
+  }
   const kept = [];
-  for (const para of paragraphs) {
-    const paraAddr = parseAddressing(para, sender, sessions);
-    if (paraAddr.targets.includes(receiverId)) {
+  paragraphs.forEach((para, i) => {
+    if (paraAddrs[i].targets.includes(receiverId)) {
       kept.push(para);
     }
-  }
+  });
   return kept.length > 0 ? kept.join(`
 
 `) : null;

plugins/orchestrator/mcp/engine/agent_channel.ts

@@ -604,6 +604,17 @@ export class AgentChannel {
  * Used by SA receivers to extract only the parts of a sender's message
  * that were addressed to them - prevents PA-to-user prose in a mixed message
  * from leaking to an SA that was named in a different paragraph.
+ *
+ * Single-recipient-set heuristic: when ALL addressed paragraphs in a message
+ * route to the same target set, the whole content is emitted (no paragraph
+ * filtering). This fixes the common-case truncation where a sender writes
+ * a directive with structural continuation paragraphs (bullets, lists,
+ * follow-up prose, closing sentences) that have no @-address of their own -
+ * under strict per-paragraph filtering those paragraphs drop, leaving the
+ * receiver with just the intro and no scope. Per-paragraph filtering is
+ * still applied to genuinely mixed-audience messages (multiple @-addresses
+ * with DIFFERENT target sets) so private user-prose paragraphs interleaved
+ * between SA-directed paragraphs continue to not leak.
  */
 function filterParagraphsForReceiver(
   content: string,
@@ -612,12 +623,33 @@ function filterParagraphsForReceiver(
   sessions: SessionEntry[],
 ): string | null {
   const paragraphs = content.split(/\n{2,}/);
+  const paraAddrs = paragraphs.map((para) =>
+    parseAddressing(para, sender, sessions),
+  );
+
+  // Collect target-set signatures of the addressed paragraphs only.
+  const targetSets = paraAddrs
+    .filter((a) => a.targets.length > 0)
+    .map((a) => [...a.targets].sort().join(","));
+  const allAddressedParagraphsShareOneTargetSet =
+    targetSets.length > 0 && targetSets.every((s) => s === targetSets[0]);
+
+  if (allAddressedParagraphsShareOneTargetSet) {
+    // Single-recipient-set message: deliver the full content (including
+    // unaddressed structural continuation paragraphs) to the target set.
+    return paraAddrs.some((a) => a.targets.includes(receiverId))
+      ? content
+      : null;
+  }
+
+  // Mixed-audience fallback: per-paragraph filtering (the original safety
+  // property from work_item b4c37849 — paragraphs addressed to a different
+  // recipient must not leak to this receiver).
   const kept: string[] = [];
-  for (const para of paragraphs) {
-    const paraAddr = parseAddressing(para, sender, sessions);
-    if (paraAddr.targets.includes(receiverId)) {
+  paragraphs.forEach((para, i) => {
+    if (paraAddrs[i].targets.includes(receiverId)) {
       kept.push(para);
     }
-  }
+  });
   return kept.length > 0 ? kept.join("\n\n") : null;
 }

plugins/orchestrator/tests/integration/agent_channel_routing.test.ts

@@ -323,4 +323,69 @@ describe("agent-channel routing E2E", () => {
       ),
     ).toBe(false);
   });
+
+  // Single-recipient-set heuristic: when ALL @-addressed paragraphs in a
+  // message route to the same target set, the WHOLE content is delivered
+  // (including unaddressed structural continuation paragraphs like bullet
+  // lists, follow-up sentences, closing prose). This fixes the common-case
+  // truncation where a sender writes a directive with structure that has
+  // no @-address of its own — under strict per-paragraph filtering those
+  // paragraphs drop, leaving the receiver with just the intro paragraph
+  // and no scope.
+  test("single-recipient message with unaddressed continuation paragraphs delivers in full", async () => {
+    const pa = makeSession("prime", "f5b8708d", "PA");
+    const sourceSa = makeSession("subordinate", "50ce0bba", "SA-source");
+    const target = makeSession("subordinate", "abc12345", "SA-target");
+    const other = makeSession("subordinate", "deadbe11", "SA-other");
+    writeSession(stateDir, pa);
+    writeSession(stateDir, sourceSa);
+    writeSession(stateDir, target);
+    writeSession(stateDir, other);
+
+    const sourceJsonl = join(projectsHashDir, `${sourceSa.session_id}.jsonl`);
+    writeFileSync(sourceJsonl, "");
+
+    // A typical PA dispatch: opening directive with @-address, then
+    // bulleted scope, then closing prose. Only the opening paragraph
+    // contains an explicit @SA-<id8> address.
+    const dispatch = [
+      "@SA-abc12345 dispatch reviewer on PR #72. Fix scope to surface in the brief:",
+      "- Patch 3 regex must match current upstream shape",
+      "- Multi-patch non-transactionality requires read-then-validate-all-then-apply",
+      "- `--help` sed range must terminate at header end (line 62)",
+      "Same branch, no new ADR, re-review through reviewer chain when meta-coder ships.",
+    ].join("\n\n");
+    appendAssistantEvent(sourceJsonl, dispatch);
+
+    const targetReceived: ChannelNotification[] = [];
+    const otherReceived: ChannelNotification[] = [];
+    const targetChan = new AgentChannel(stateDir, projectsHashDir, target, (n) =>
+      targetReceived.push(n),
+    );
+    const otherChan = new AgentChannel(stateDir, projectsHashDir, other, (n) =>
+      otherReceived.push(n),
+    );
+    targetChan.start();
+    otherChan.start();
+    await new Promise((r) => setTimeout(r, 50));
+    targetChan.stop();
+    otherChan.stop();
+
+    // SA-target receives the FULL content (intro + bullets + closing).
+    const targetContents = targetReceived
+      .filter((n) => n.meta.event_type === "assistant_text")
+      .map((n) => n.content);
+    expect(targetContents.length).toBe(1);
+    const got = targetContents[0];
+    expect(got).toContain("dispatch reviewer on PR #72");
+    expect(got).toContain("Patch 3 regex must match");
+    expect(got).toContain("Multi-patch non-transactionality");
+    expect(got).toContain("`--help` sed range");
+    expect(got).toContain("Same branch, no new ADR");
+
+    // SA-other (not addressed) receives nothing.
+    expect(
+      otherReceived.some((n) => n.meta.event_type === "assistant_text"),
+    ).toBe(false);
+  });
 });