Add a sidebar viewer for linked issues, like Pull Requests

[PixPMusic]

Problem or use case

T3's Pull Requests viewer lets me read a PR/MR and follow its discussion without leaving the app. I want the same experience for the issues and tickets linked to my threads.

An issue URL attached to a thread is useful, but I still have to open GitHub, GitLab, or Jira to read the description, check its fields, and catch up on comments. Issue linking should give me a way to view that work inside T3 too.

Proposed solution

Add a sidebar entry point to a viewer for linked issues, using the existing Pull Requests viewer as the model.

The viewer should let me:

• See issues linked to T3 threads, with their identifier, title, and status.
• Open a Summary tab with the issue title, description, and comment timeline. Internal notes and public replies should be clearly distinguished where the tracker supports that distinction.
• Switch to a Properties tab containing the full set of available fields, including standard fields and custom fields.
• Pin important fields from Properties so their current values appear in Summary, below the title and above the description. Unpinning removes a field from Summary while keeping it available in Properties. Pinning is a local display preference and does not change the source issue.
• Link or unlink an issue from a thread.
• Open the issue in its source tracker.

The existing Pull Requests viewer could be extended to support linked issues too, reusing its list/detail patterns. The goal is an in-app issue viewer accessible from the sidebar, with PRs/MRs remaining available as well.

Smallest useful scope

Start with viewing issues already linked to threads: issue details and a paginated comment timeline. Keep tracker operations read-only for this slice.

GitHub/GitLab can use their existing CLIs. For Jira, Atlassian's Teamwork Graph CLI (twg) looks like a practical path: a read-only check confirmed issue fields, custom fields, and paginated comments with explicit internal/public visibility.

Agent-facing T3 tools can mirror existing PR link/unlink/list tools. Agents can read issue details directly through the tracker CLI, as they already use gh/glab for PRs and MRs.

The viewer should be reachable on web, desktop, and mobile, using the connected environment's issue data.

Local prototype and comparison

The local UI prototype has both tabs and pin/unpin behavior. Summary shows pinned current field values above the description, followed by the comment timeline. Properties exposes every available fixture field, including custom, list, empty, and nested values. Pins persist per issue in this browser, with only field IDs saved.

The comparisons below use the actual MR viewer on the left and the issue prototype on the right, at the same 1280 × 1440 viewport in dark mode. All records, people, projects, and tracker URLs are fictional; the screenshots contain no employer data or machine hostname.

Existing MR viewer	Linked issue viewer
Summary contains description and comments, with review metadata above them.	Summary contains description and comments, with selected properties above them and explicit Internal/Public visibility.
Review-specific tabs and controls remain available.	Properties is a separate tab for the full available field set; its pin controls choose what appears in Summary.

The code remains local. This is a web UI prototype shared by the web and desktop clients; native mobile and live tracker/linking integration are still later work. Focused preference/fixture tests, web typecheck, scoped lint, and an integrated browser pass cover pinning, reload persistence, unpinning, issue isolation, sidebar/Back navigation, and narrow layouts.

Related proposals

• #11785 covers linking issues to threads. This proposal makes the sidebar-accessible issue viewer explicit.
• #11067 proposes an Issues panel for browsing repository issues. This is closely related; the focus here is viewing issues already linked to threads, including Jira tickets.

I am opening this in Ideas to agree on direction and scope. The local prototype above is available for discussing the layout and behavior. No PR is attached.