refactor(chat): locate iMessage progress policy in channel folder

Co-Authored-By: Paperclip <noreply@paperclip.ing>

doc/plans/2026-10-10-chat-channels-refactor.md

@@ -220,3 +220,16 @@ by the service. No state or registration moves in this slice.
 - Existing CI fixtures cover exact outbound ownership, interleaved control
   messages, consumed progress, interactions, committed failure replacement and
   issue-to-run lock order. Local database capacity remains blocked.
+
+### 2026-10-12 channel-folder reassessment: slice 4
+
+Publication replacement is shared ownership logic: exact outbound links, run and
+wake scope, consumed progress messages, interaction prompts and retained-source
+authorization. Keep those queries together. The close-message provider allowlist
+is shared dispatch metadata, not four separate implementations.
+
+Move the iMessage queued/working suppression policy and explanation to
+`imessage-photon/publications.ts`. Preserve when endpoint lookup occurs and leave
+all ownership queries unchanged. Baseline: 49 public-service publication and
+Photon cases passed, including close-owned progress, interleaved Slack control,
+Telegram confirmation and FIFO replacement. The same 49 cases passed after. Server typecheck and module boundaries pass.

server/src/services/chat-channels/imessage-photon/publications.ts

@@ -0,0 +1,9 @@
+import type { SafeChatPublicationPayload } from "@paperclipai/shared";
+
+export function imessageProgressSupersessionReason(
+  progress: SafeChatPublicationPayload["progressState"],
+): string | null {
+  return progress && ["queued", "working"].includes(progress)
+    ? "iMessage uses typing instead of progress bubbles"
+    : null;
+}

server/src/services/chat-channels/publication-replacement.ts

@@ -1,3 +1,4 @@
+import { imessageProgressSupersessionReason } from "./imessage-photon/publications.js";
 import { fastResponseRequests } from "@paperclipai/db";
 
 import {
@@ -74,9 +75,10 @@ export function createChatPublicationReplacement(db: Db, options: ChatPublicatio
     publication: typeof chatPublications.$inferSelect,
   ): Promise<string | null> {
     const progress = publication.payload.progressState;
-    if (progress && ["queued", "working"].includes(progress)) {
+    const typingReason = imessageProgressSupersessionReason(progress);
+    if (typingReason) {
       const endpoint = await endpointRecord(publication.endpointId);
-      if (endpoint?.endpoint.provider === "imessage-photon") return "iMessage uses typing instead of progress bubbles";
+      if (endpoint?.endpoint.provider === "imessage-photon") return typingReason;
     }
     if (
       !progress ||