fix: show empty project thread state in sidebar

[shivamhwp]

Fixes #358

What Changed

This PR adds an explicit empty state in the sidebar for projects that do not have any threads yet.

When a project is expanded and its thread list is empty, the sidebar now shows a row styled consistently with the existing thread-list controls, using the text No threads yet.

Why

Issue #358 asked for an explicit empty state in the sidebar.

Before this change, an empty project thread list looked blank, which made the UI feel incomplete and ambiguous. This keeps the behavior minimal and focused: it does not add any new interaction, only a clear visual indication that the project currently has no threads.

UI Changes

Before:

After:

Checklist

• This PR is small and focused
• I explained what changed and why
• I included before/after screenshots for any UI changes
• I included a video for animation/interaction changes

---

Note

Low Risk
Low risk UI-only change that adds a placeholder row when an expanded project has zero threads; minimal logic added and covered by a browser test.

Overview
Shows an explicit empty thread list placeholder in the sidebar: when a project is expanded and has no threads, the thread panel now renders a styled row labeled No threads yet instead of appearing blank.

Adds a browser regression test in ChatView.browser.tsx asserting the empty-state text appears for a project snapshot with no threads.

^{Written by Cursor Bugbot for commit 1bef412. This will update automatically on new commits. Configure here.}

Note

Show 'No threads yet' placeholder in sidebar when a project has no threads

Adds a showEmptyThreadState flag in Sidebar.tsx that is true when a project is expanded and has zero threads. When the thread panel is visible and this flag is set, a SidebarMenuSubItem with the label 'No threads yet' is rendered. A browser test in ChatView.browser.tsx verifies the empty state message appears for a draft-only snapshot.

^{Macroscope summarized 1bef412.}

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on this repository. Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro

Run ID: c00b277e-46b4-4caa-b1fb-8c1984931af4

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}