[FEATURE] Desktop: assign folders to custom sidebar groups so new sessions are filed automatically

TL;DR: Let me assign a folder to a custom sidebar group, so every session started in that folder lands in that group automatically. Neither existing mode does this; each has what the other lacks: | | Combine several folders in one group | New sessions filed automatically | |---|---|---| | Group by → Folder | ✗ | ✓ | | Group by → Custom groups | ✓ | ✗ (they land in "Ungrouped", see #69105) | | This request | ✓ | ✓ |

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 sidebar offers Group by: Date, Folder, State, Custom groups, None. None of them lets me organize my projects (folders) into groups:

• Folder creates one section per working directory. Related repositories can't be combined into one section.
• Custom groups works at the session level. A group contains sessions, not folders, so there is no way to say "everything from this folder goes to group X". Every session, including each new one, has to be moved by hand (right-click → Move to group). With several new sessions a day, I end up filing sessions manually or searching for them in the list.

In the Codex app I create groups once and move existing project folders into them. I'd like the same model here.

Proposed Solution

Groups whose members are folders, not sessions:

1. Create a named group in the sidebar.
2. Add folders to it: drag a folder section into the group, or right-click a folder → Move to group → pick an existing group or create a new one.
3. Every session whose working directory is one of the group's folders appears under that group automatically, both existing and future sessions. No per-session filing.
4. Worktree sessions belong to their source repository's folder, regardless of the worktree location setting.
5. Inside a group, sessions stay grouped by folder (collapsible): group → folder → sessions.
6. A folder belongs to at most one group. Folders without a group are listed after all groups.

Minimal version

This alone would solve it, as a small extension of Custom groups:

• Session or group context menu: "Always put sessions from <folder> here".
• New sessions whose working directory is that folder (or one of its worktrees) go to that group instead of "Ungrouped".
• When the rule is created, existing sessions from that folder move once.

Alternative Solutions

• Group by → Folder: automatic, but one section per repo; related repos can't be combined.
• Group by → Custom groups: can combine anything, but only session by session; every new session has to be filed manually.
• Start sessions from a common parent folder (e.g. C:\src\orders): sessions land in one section, but the parent becomes the working directory, so worktree isolation isn't available (the parent isn't a git repository) and per-repo .claude/ config (settings, launch.json) no longer applies.
• Prefixing session names ([Orders] ...): manual and doesn't create sections.

Priority

Medium - Would be very helpful

Feature Category

Other (Desktop app, Code tab sidebar)

Use Case Example

Folders on disk:

C:\src\orders-api
C:\src\orders-web
C:\src\orders-contracts
C:\src\billing-service
C:\src\my-mcp-server
C:\src\dotfiles

Today (Group by → Folder): six separate sections, one per folder:

billing-service
orders-web
dotfiles
orders-api
my-mcp-server
orders-contracts

Desired:

▾ Orders
   ▾ orders-api
        Fix outbox retry on Kafka timeout
        Add idempotency key to POST /orders
   ▾ orders-web
        Checkout form validation
   ▸ orders-contracts
▾ Billing
   ▾ billing-service
        Consumer lag investigation
▾ Side projects
   ▸ my-mcp-server
   ▸ dotfiles

A new session started in C:\src\orders-api shows up under Orders → orders-api immediately.

Additional Context

Earlier requests that were closed without covering this:

• #59982: auto-assign sessions to groups by working directory. Closed with "You can group by project in the sidebar", which gives one section per folder and can't combine repos.
• #60954: same answer; the author replied: "That was not the feature that I was after".
• #69105: in Custom groups, new sessions land in "Ungrouped" even when they have a working directory (closed as stale).

Related:

• #70104: a comment there lays out that Custom groups and Group by → Project each lack what the other has, so no setting gives both.
• #82641, #81914: manual groups of sessions (now available as Custom groups)
• #58193: Custom groups bugs (groups disappearing, Move to group offering only "Create new group")

This request combines the two modes: user-defined groups, as in Custom groups, with membership set per folder and applied automatically, as in Group by → Folder.

Environment: Claude Desktop 2.9939.4, Windows 11, Code tab.