fix(desktop): retain automatic mentions only in threads (#7144)

**Category:** fix
**User Impact:** Top-level channel messages now notify only agents
explicitly selected for that message, while thread replies visibly
retain their addressed agents.

**Problem:** Channel-root and thread composers presented the same
automatic-mention model even though retained recipients are only
predictable within an ongoing thread. That could make a new top-level
message notify an agent the sender did not deliberately choose for that
message.

**Solution:** Make retained audiences a thread-only capability. Root
messages remain explicit and one-shot; threads retain visible, removable
agent recipients, with the automatic-mention setting exposed directly in
the mention picker.

<details>
<summary>File changes</summary>

**desktop/src/features/channels/ui/ChannelPane.tsx**
Removes persistent audience state from the channel-root composer.

**desktop/src/features/messages/ui/ComposerAddressControls.tsx**
Uses the broader **Manage mentions** label because the picker includes
people as well as automatic agent controls.

**desktop/src/features/messages/ui/ComposerAddressControls.test.mjs**
Locks the updated accessible label and active treatment.

**desktop/src/features/messages/ui/MentionAutocomplete.tsx**
Shows the right-aligned automatic-mention setting directly, uses
thread-specific copy, preserves keyboard/focus behavior, and keeps the
current mention when retention is unchecked.

**desktop/src/features/messages/ui/MentionAutocomplete.test.mjs**
Covers the always-visible setting, compact layout, copy, and
thread-scoped agent actions.

**desktop/src/features/messages/ui/MessageComposer.tsx**
Separates unpinning an agent for future replies from removing its
current draft mention.

**desktop/src/features/messages/ui/MessageComposer.types.ts**
Narrows retained audience contexts to threads.


**desktop/src/features/messages/ui/persistentAgentAudienceHosts.test.mjs**
Prevents channel-root and new-message hosts from opting back into
retained audiences.

**desktop/src/features/messages/ui/useAgentAddressLockPicker.ts**
Splits unpin and current-mention removal semantics.

**desktop/src/features/messages/ui/useAgentAddressLockPicker.test.mjs**
Verifies unpinning retains the current draft mention.

**desktop/src/features/settings/ui/AgentsSettingsPanel.tsx**
Describes the preference as addressing selected agents in thread
replies.

**desktop/tests/e2e/persistent-agent-audience.spec.ts**
Moves retained-audience lifecycle coverage to thread composers and adds
root, settings, layout, focus, keyboard, unpin, and draft regressions.

**desktop/src/features/messages/ui/MessageComposerAutocompletes.tsx**
Preserves composer focus ownership while routing the thread-only
controls.

**desktop/src/features/messages/ui/useComposerFocusOwnership.ts**
Keeps focus within the composer while interacting with its mention
overlay controls.

</details>

### Reproduction steps

1. Enable **Automatically mention agents** under agent settings.
2. In a channel root, select an agent and send a message. Confirm the
agent is addressed once, no retained-recipient control appears, and the
next root message has no agent recipient.
3. Open a thread and select an agent. Confirm the visible recipient
persists into later replies.
4. Open **Manage mentions** in the thread composer. Confirm the
automatic-mention setting is immediately visible, right-aligned, and
labeled **Address selected agents in thread replies**.
5. Uncheck a selected agent. Confirm its current draft mention remains,
while later replies no longer retain it automatically.

---------

Signed-off-by: Taylor Ho <taylorkmho@gmail.com>
Co-authored-by: Rizz <302abe414ca6e3134763d2539bfcf145aea2a63fe5f8455204ed602fd40cf381@buzz.block.builderlab.xyz>
Co-authored-by: Carl <acda9e433d19dcd0e6b6840f7f4b98f3a56f1fab98049d444c087019e6d36560@buzz.block.builderlab.xyz>

Author: 3 people

desktop/src/features/channels/ui/ChannelPane.tsx

@@ -754,7 +754,6 @@ export const ChannelPane = React.memo(function ChannelPane({
                   ) : null}
                   <ComposerDockBackdrop gutterClassName="inset-x-5" />
                   <MessageComposer
-                    audienceContext={{ type: "channel" }}
                     channelId={activeChannel?.id ?? null}
                     channelName={activeChannel?.name ?? "channel"}
                     channelType={activeChannel?.channelType ?? null}

desktop/src/features/home/ui/InboxDetailPane.tsx

@@ -495,6 +495,10 @@ function InboxMessageDetailPane({
       : null;
   const isThreadContext =
     !isDirectMessage && hasInboxThreadContext(item, messages);
+  const threadRootTags = isThreadContext
+    ? (displayMessages.find((message) => message.id === item.conversationId)
+        ?.tags ?? [])
+    : [];
   const contextLabel = isThreadContext
     ? isDirectMessage
       ? `Thread with ${item.senderLabel}`
@@ -804,7 +808,14 @@ function InboxMessageDetailPane({
           />
           <div className="pointer-events-auto">
             <MessageComposer
-              audienceContext={isDirectMessage ? null : { type: "thread" }}
+              audienceContext={
+                isDirectMessage
+                  ? null
+                  : {
+                      type: "thread",
+                      rootTags: threadRootTags,
+                    }
+              }
               channelId={item.item.channelId}
               channelName={item.channelLabel ?? "channel"}
               channelType={composerChannelType}

desktop/src/features/messages/lib/persistentAgentAudience.test.mjs

@@ -219,6 +219,21 @@ test("explicitly excluded agents are not auto-promoted again", async () => {
   assert.deepEqual(currentAudiences(store), { [scope]: [agentA] });
 });
 
+test("initialization preserves exclusions across thread remounts", async () => {
+  const store = await loadStore(14);
+  const scope = `${ownerA}:channel-a:thread-a`;
+
+  store.initializePersistentAgentAudience(scope, [agentA]);
+  assert.deepEqual(currentAudiences(store), { [scope]: [agentA] });
+
+  store.excludePersistentAgentAudienceMember(scope, agentA);
+  store.initializePersistentAgentAudience(scope, [agentA]);
+  assert.deepEqual(currentAudiences(store), { [scope]: [] });
+
+  store.addPersistentAgentAudienceMember(scope, agentA);
+  assert.deepEqual(currentAudiences(store), { [scope]: [agentA] });
+});
+
 test("explicit re-selection reinstates an excluded agent", async () => {
   const store = await loadStore(13);
   const scope = `${ownerA}:channel-a:channel`;

desktop/src/features/messages/lib/persistentAgentAudience.ts

@@ -160,6 +160,23 @@ export function removePersistentAgentAudienceMembersIfUnchanged({
   return true;
 }
 
+export function initializePersistentAgentAudience(
+  scope: string,
+  pubkeys: Iterable<string>,
+): void {
+  if (!scope) return;
+  const excluded = excludedPubkeysByScope.get(scope);
+  const initialPubkeys = normalizePubkeys(pubkeys).filter(
+    (pubkey) =>
+      !(audiences[scope] ?? []).includes(pubkey) && !excluded?.has(pubkey),
+  );
+  if (initialPubkeys.length === 0) return;
+  setPersistentAgentAudience(scope, [
+    ...(audiences[scope] ?? []),
+    ...initialPubkeys,
+  ]);
+}
+
 export function addPersistentAgentAudienceMember(
   scope: string,
   pubkey: string,

desktop/src/features/messages/ui/ComposerAddressControls.test.mjs

@@ -72,7 +72,7 @@ test("mention control expands with automatically mentioned agents", async () =>
   const avatar = view.getByTestId("composer-address-lock-agent-pubkey");
   assert.ok(avatar);
   const manage = view.getByRole("button", {
-    name: "Manage automatic agent mentions",
+    name: "Manage mentions",
   });
   assert.match(manage.className, /(?:^|\s)-ml-2(?:\s|$)/);
   assert.match(manage.className, /(?:^|\s)pl-2(?:\s|$)/);
@@ -82,18 +82,18 @@ test("mention control expands with automatically mentioned agents", async () =>
     /(?:^|\s)pr-1\.5(?:\s|$)/,
   );
   assert.match(
-    view.getByRole("button", { name: "Manage automatic agent mentions" })
-      .parentElement?.className ?? "",
+    view.getByRole("button", { name: "Manage mentions" }).parentElement
+      ?.className ?? "",
     /(?:^|\s)bg-primary\/15(?:\s|$)/,
   );
   assert.match(
-    view.getByRole("button", { name: "Manage automatic agent mentions" })
-      .parentElement?.className ?? "",
+    view.getByRole("button", { name: "Manage mentions" }).parentElement
+      ?.className ?? "",
     /(?:^|\s)text-primary(?:\s|$)/,
   );
   assert.doesNotMatch(
-    view.getByRole("button", { name: "Manage automatic agent mentions" })
-      .parentElement?.className ?? "",
+    view.getByRole("button", { name: "Manage mentions" }).parentElement
+      ?.className ?? "",
     /(?:^|\s)bg-accent\/70(?:\s|$)/,
   );
   assert.doesNotMatch(
@@ -110,7 +110,13 @@ test("mention control expands with automatically mentioned agents", async () =>
       /scale\(0.8\)/,
     );
   }
-  const remove = view.getByTestId("composer-address-lock-remove-agent-pubkey");
+  const remove = view.getByRole("button", {
+    name: "Don't automatically mention Agent Ada in this thread",
+  });
+  assert.equal(
+    remove.getAttribute("aria-label")?.includes("conversation"),
+    false,
+  );
   const removeChrome = remove.querySelector("span.absolute");
   assert.match(
     removeChrome?.className ?? "",

desktop/src/features/messages/ui/ComposerAddressControls.tsx

@@ -180,11 +180,7 @@ export function ComposerMentionButton({
           <Tooltip disableHoverableContent>
             <TooltipTrigger asChild>
               <button
-                aria-label={
-                  hasAgents
-                    ? "Manage automatic agent mentions"
-                    : "Mention someone"
-                }
+                aria-label={hasAgents ? "Manage mentions" : "Mention someone"}
                 className={cn(
                   "flex h-8 items-center justify-center rounded-lg focus-visible:outline-hidden focus-visible:ring-1 focus-visible:ring-ring disabled:pointer-events-none disabled:opacity-50",
                   showActiveChrome
@@ -205,9 +201,7 @@ export function ComposerMentionButton({
               </button>
             </TooltipTrigger>
             <TooltipContent>
-              {hasAgents
-                ? "Manage automatic agent mentions"
-                : "Mention someone"}
+              {hasAgents ? "Manage mentions" : "Mention someone"}
             </TooltipContent>
           </Tooltip>
           <AnimatePresence
@@ -234,7 +228,7 @@ export function ComposerMentionButton({
                     <Tooltip disableHoverableContent key={agent.pubkey}>
                       <TooltipTrigger asChild>
                         <motion.button
-                          aria-label={`Don't automatically mention ${agent.displayName} in this conversation`}
+                          aria-label={`Don't automatically mention ${agent.displayName} in this thread`}
                           animate={{ opacity: 1, scale: 1 }}
                           className="group/address relative rounded-full focus-visible:outline-hidden focus-visible:ring-1 focus-visible:ring-ring"
                           data-testid={`composer-address-lock-remove-${agent.pubkey}`}
@@ -276,7 +270,7 @@ export function ComposerMentionButton({
                       </TooltipTrigger>
                       <TooltipContent>
                         Don't automatically mention {agent.displayName} in this
-                        conversation
+                        thread
                       </TooltipContent>
                     </Tooltip>
                   ))}