[FEATURE REQUEST] Cowork: Set a default project folder that auto-loads on session start

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

Summary
When starting a new Cowork session, users must manually select their working folder every time via the project picker. There's no way to set a persistent default.

Current behaviour
Each new session starts with no folder selected. Users must manually pick their folder before any file operations can proceed.

Why it matters
Power users who always work from the same folder (e.g. a personal knowledge base or assistant workspace) lose a small but consistent amount of friction every session. It also means any automated or scheduled tasks can't rely on the folder being present without a manual step first.

Proposed Solution

Desired behaviour
Allow users to designate a folder as their default Cowork workspace, so it's automatically mounted at the start of every new session — without having to click the folder picker each time.

Alternative Solutions

No real workaround exists. The only option is manually selecting the folder at the start of every session. I've added a reminder to my assistant's instructions to check for the folder and warn me if it's missing, but that really can't work because if I'm not in the right folder, then those instructions are not read.

Priority

Medium - Would be very helpful

Feature Category

Configuration and settings

Use Case Example

I maintain a personal assistant workspace in Obsidian (/Users/T890438/Documents/Obsidian Vault/Robot_Assistant/). Every Cowork session I start, my first step is always to manually select that folder before I can do anything useful. If I forget, the assistant either fails on file operations or mounts the wrong location. My CLAUDE.md even has an explicit reminder to warn me if the folder isn't mounted — because it's that easy to miss.

Additional Context

_No response_