[Feature]: Default Plan Mode setting for new workspaces

[jackthedev]

Platform

macOS

Operating system version

Tahoe 26.5.1

System architecture

ARM

PolyScope Version

0.21.0

Bug description

There's currently no way to make new workspaces start Claude sessions in plan mode by default - it has to be toggled manually on every workspace. Reviewing a plan before the agent edits is a common workflow, and Coding Agents → Default Parameters already has per-workspace defaults for Claude Effort Level and Fast Mode - a "Plan Mode" default alongside them feels like the natural place.

This also can't be achieved via Claude Code itself: setting permissions.defaultMode: "plan" in the repo's .claude/settings.json works when running the claude CLI directly in the repo and the file is present in the workspace clone, but Polyscope sessions start in normal mode regardless - presumably because the session is launched with an explicit permission mode that takes precedence over project settings.

Either approach would solve it:

1. A Plan Mode default in Default Parameters (per-workspace override via the existing toolbar toggle), or
2. Respecting permissions.defaultMode from the repo's .claude/settings.json when the user hasn't explicitly toggled a mode.

Steps to reproduce

1. In a repo root, create .claude/settings.json containing:
   { "permissions": { "defaultMode": "plan" } }
2. Run claude directly in that repo - the session starts with "plan mode on" in the status bar (setting works)
3. Create a new Polyscope workspace from the same repo
4. Confirm .claude/settings.json is present in the workspace clone (cat .claude/settings.json)
5. Start a Claude session in the workspace - it starts in normal mode instead of plan mode

Relevant log output

$ cd ~/Projects/my-laravel-app
$ claude
Claude Code v2.1.175
plan mode on (shift+tab to cycle)

# Same repo via a Polyscope workspace:
$ cat .claude/settings.json
{ "permissions": { "defaultMode": "plan", ... } }
# session starts in normal mode