fix(desktop): prioritize sidebar channel status (#6861)

## Summary

- Treat the sidebar temp-channel icon as a fallback behind working,
mute, numeric unread, and thread-unread indicators.
- Keep the header affordance and the sidebar temp icon when it is the
only row status.
- Extend the ephemeral-channel browser scenario across working, idle,
collapsed-sidebar, and unread states.

## Before / After

| Before: five temp icons compete with duration and unread states |
After: all five duration and unread states remain clear |
| --- | --- |
| ![Before: five long temporary channel rows each show a temp icon, long
duration, and unread
state](https://d24qwcpro867f5.cloudfront.net/repos/buzz/prs/6861/temp-icon-before-five.png)
| ![After: the same five long temporary channel rows retain long
durations and unread states without temp
icons](https://d24qwcpro867f5.cloudfront.net/repos/buzz/prs/6861/temp-icon-after-five.png)
|

## Testing

- `node --import ./test-loader.mjs --experimental-strip-types --test
"src/**/*.test.mjs"` (5,556 passed)
- `tsc --noEmit -p desktop/tsconfig.json`
- `biome check desktop/src/features/sidebar/ui/SidebarSection.tsx
desktop/tests/e2e/channels.spec.ts`
- `vite build --mode e2e`
- Isolated Playwright run of `create ephemeral stream shows sidebar and
header affordances` (1 passed)

## Duplicate check

No matching open PR or issue found for `ephemeral sidebar icon`.

Signed-off-by: Jitter <d14dfe033ef0f809866f9f984de04821b0d900d7652fd85a54776ee40ca3a68f@buzz.block.builderlab.xyz>
Co-authored-by: Jitter <d14dfe033ef0f809866f9f984de04821b0d900d7652fd85a54776ee40ca3a68f@buzz.block.builderlab.xyz>

desktop/src/features/sidebar/ui/SidebarSection.tsx

@@ -294,6 +294,14 @@ export function ChannelMenuButton({
     (hasSidebarUnreadProjections
       ? unreadThreadChannelIds.has(channel.id)
       : hasUnread);
+  const showsUnreadCount =
+    !isActive && channel.channelType !== "dm" && unreadCount > 0;
+  const showsEphemeralBadge =
+    Boolean(ephemeralDisplay) &&
+    !activeWorking &&
+    !isMuted &&
+    !showsUnreadCount &&
+    !hasThreadUnread;
   const inactiveContentOpacity = cn(
     !isActive && !hasTopLevelUnread && !isMuted && "opacity-80",
     !isActive &&
@@ -334,7 +342,7 @@ export function ChannelMenuButton({
       >
         {resolvedLabel}
       </span>
-      {ephemeralDisplay ? (
+      {showsEphemeralBadge && ephemeralDisplay ? (
         <EphemeralChannelBadge
           display={ephemeralDisplay}
           testId={`channel-ephemeral-${channel.name}`}
@@ -358,7 +366,7 @@ export function ChannelMenuButton({
           )}
         />
       ) : null}
-      {!isActive && channel.channelType !== "dm" && unreadCount > 0 ? (
+      {showsUnreadCount ? (
         <UnreadCountBadge
           channelName={channel.name}
           className="ml-auto bg-notification text-notification-foreground"

desktop/tests/e2e/channels.spec.ts

@@ -34,6 +34,8 @@ type MockFeedWindow = Window & {
     content: string;
     createdAt?: number;
     id?: string;
+    kind?: number;
+    mentionPubkeys?: string[];
     parentEventId?: string;
     pubkey?: string;
   }) => {
@@ -1581,12 +1583,78 @@ test("create ephemeral stream shows sidebar and header affordances", async ({
     /Ephemeral channel\. Cleans up in 14 days\./,
   );
 
+  const channelRow = page.getByTestId(`channel-${channelName}`);
+  const channelId = await channelRow.getAttribute("data-channel-id");
+  if (!channelId) {
+    throw new Error("Created ephemeral channel is missing its channel id.");
+  }
+
+  await waitForMockLiveSubscription(page, channelName);
+  await page.getByTestId("channel-general").click();
+  await page.evaluate(
+    ({ agentPubkey, channelId: activeChannelId }) => {
+      (window as MockFeedWindow).__BUZZ_E2E_SEED_ACTIVE_TURNS__?.({
+        agentPubkey,
+        channelId: activeChannelId,
+        turnId: "ephemeral-sidebar-status",
+      });
+    },
+    { agentPubkey: OWNED_RELAY_AGENT_PUBKEY, channelId },
+  );
+
+  await expect(
+    page.getByTestId(`channel-working-${channelName}`),
+  ).toBeVisible();
+  await expect(
+    page.getByTestId(`channel-ephemeral-${channelName}`),
+  ).toHaveCount(0);
+
+  await page.evaluate(
+    ({ agentPubkey, channelId: activeChannelId }) => {
+      (window as MockFeedWindow).__BUZZ_E2E_SEED_ACTIVE_TURNS__?.({
+        agentPubkey,
+        channelId: activeChannelId,
+        turnId: "ephemeral-sidebar-status",
+        kind: "turn_completed",
+      });
+    },
+    { agentPubkey: OWNED_RELAY_AGENT_PUBKEY, channelId },
+  );
+  await expect(
+    page.getByTestId(`channel-ephemeral-${channelName}`),
+  ).toBeVisible();
+
   await page
     .getByRole("button", { name: "Toggle Sidebar", exact: true })
     .click();
   await expect(
     page.getByTestId(`channel-ephemeral-${channelName}`),
   ).toBeVisible();
+  await page
+    .getByRole("button", { name: "Toggle Sidebar", exact: true })
+    .click();
+
+  await page.evaluate(
+    ({ channelName: targetChannelName, mentionPubkey, senderPubkey }) => {
+      (window as MockFeedWindow).__BUZZ_E2E_EMIT_MOCK_MESSAGE__?.({
+        channelName: targetChannelName,
+        content: "Unread mention in an ephemeral channel",
+        kind: 40002,
+        mentionPubkeys: [mentionPubkey],
+        pubkey: senderPubkey,
+      });
+    },
+    {
+      channelName,
+      mentionPubkey: MOCK_IDENTITY_PUBKEY,
+      senderPubkey: TEST_IDENTITIES.alice.pubkey,
+    },
+  );
+
+  await expect(page.getByTestId(`channel-unread-${channelName}`)).toBeVisible();
+  await expect(
+    page.getByTestId(`channel-ephemeral-${channelName}`),
+  ).toHaveCount(0);
 });
 
 test("ephemeral countdown refreshes when switching channels after a clock jump", async ({