fix(app): auto-accept toggle disabled when no session is open

Description

The Settings → General auto-accept permissions switch is greyed out whenever no session is open (home / new-session / draft views). Possibly the same family as #37617 / #45159 / #31137 — this report adds a root-cause analysis and a tested fix design: createPermissionScopeController resolves its directory only from session lineage, and the settings dialog never forwards the route directory it already computes.

Reproduction

1. Open the app with no session (home / new-session view)
2. Go to Settings → General
3. The auto-accept permissions switch is disabled (no directory context)
4. Open any session → the switch works (session lineage supplies the directory)

Environment

• opencode v1.18.29 (source build), Linux; likely all platforms / distributions
• No session open (home / draft views)

Suggested fix

Add a fallbackDirectory to the controller (session lineage first, route directory otherwise) and thread directory() from DialogSettings through SettingsGeneralV2. With no session, the switch reflects and writes the directory-level flag, which new sessions already inherit on submit (submit.ts shouldAutoAccept → enableAutoAccept). The switch stays disabled only when no directory is known at all. Tested locally (3 files, +25/−9); patch available on request.