[FEATURE] Desktop file pane: add a project tree so files can be opened without a path in chat

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

The Code tab's file pane can only be reached two ways, and both assume I already know which file I want:

| Entry point | Requires |
|---|---|
| Clicking a file path in chat or the diff viewer | Claude already mentioned that exact file |
| @ autocomplete in the prompt box | I already know the filename |

There is no way to open a file I haven't talked about and can't name. The docs are explicit that the pane is path-driven: "Click a file path in the chat or diff viewer to open it in the file pane."

That gap matters because a lot of real work is browsing-shaped rather than search-shaped. I use the Code tab on a repository that is mostly documentation — ~170 Markdown files in a numbered hierarchy (00-overview/, 01-product/, 02-decisions/, …) kept alongside the code as a project knowledge base. When I want to know what decisions exist about a topic, the answer comes from scanning a folder, not from guessing filenames. The same is true when onboarding onto an unfamiliar part of any codebase.

Right now each of those lookups costs me either a trip out to Finder/VS Code, or a model round trip asking Claude to ls so I get a clickable path in the reply. Spending an agent turn to produce a path that a tree view would show instantly is the wrong shape for the task.

On a single monitor it is worse: keeping an editor open beside the app purely to get a file tree undercuts the reason the integrated file pane exists.

Proposed Solution

Add a project tree as an entry point to the file pane that already exists — not a new pane, and not an IDE.

• A toggleable tree rooted at the session's working directory, inside the file pane or as a tab within it
• Clicking a node opens that file in the file pane exactly as clicking a chat path does today
• Same treatment as the other panes: a Views menu entry and a keyboard shortcut, alongside the existing Cmd+Shift+D, Cmd+Shift+B, and `Ctrl+ ``

Everything downstream is already built — the viewer, spot editing, Save, the "changed on disk" warning, Discard, copy-absolute-path. The only missing piece is a way to reach a file that hasn't come up in the conversation yet.

Nice to have, not required:

• Respect .gitignore so node_modules and build output don't drown the tree
• Mark files touched in the current session, so the tree doubles as a "what did Claude just change" view

Alternative Solutions

• @ autocomplete — works when I know the filename. It is a search box, not a browser; it can't answer "what's in this folder?"
• Asking Claude to ls and clicking a path out of the reply — works, but spends a model turn on something a tree answers instantly, and those paths scroll away as the conversation grows
• Keeping VS Code or Finder open beside the app — what I do now. Costs half the screen on a single monitor, and means the integrated file pane isn't the thing I actually navigate with
• **The integrated terminal (`Ctrl+ `)** — ls` there gives me text I still can't click

Priority

Medium - Would be very helpful

Feature Category

File operations

Use Case Example

1. I open my project in the Code tab. It has a 02-decisions/ folder holding ~40 decision records, named DR-0001-....md through DR-0039-....md.
2. I want to check whether we already decided something about push notifications. I don't remember the number or the exact filename — I only know which folder it would be in.
3. Today: I either switch to VS Code and scroll the folder, or I type "list what's in 02-decisions", wait for Claude to run ls, and click the path I want out of its reply.
4. With a project tree: I expand 02-decisions/, scan ~40 filenames, click the one that looks right. It opens in the file pane I already have open.
5. Step 4 takes a second or two. Step 3 is either an app switch or a model round trip — and it happens many times an hour when the work is reading rather than writing.

Additional Context

Environment: Claude Desktop 1.32885.1, macOS 26.5.2 (Apple Silicon), Code tab, local session.

Docs reference: Desktop application — "Click a file path in the chat or diff viewer to open it in the file pane."

Related issues, and why I believe this one is distinct:

• #24300 asks for a full standalone lightweight IDE. This request is much narrower — one entry point on a pane that already ships.
• #38439 is the same underlying need but filed against Cowork; closed as not planned.
• #61400 reports the file explorer collapsing when a file is opened; closed as duplicate.