Add recent plans menu and restore open plans on startup

[erikdarlingdata]

Summary

Two related quality-of-life features for plan file management:

1. Recent Plans menu item (File > Recent Plans)

• Track the last N (10?) opened .sqlplan files
• Show as a submenu under File with full path, most recent first
• Persist the list to a local settings file (e.g., recent_plans.json in app data)
• Include a "Clear Recent" option at the bottom

2. Restore open plans on startup

• On close, save the list of currently open plan session paths to the settings file
• On startup, automatically reload those plans so the user picks up where they left off
• Handle gracefully if a file was moved/deleted since last session (skip with no error)

Notes

• Both features share the same persistence mechanism (app settings / JSON file)
• Plans opened via clipboard paste or Query Store fetch won't have file paths — only file-based plans should be tracked

🤖 Generated with Claude Code

[erikdarlingdata]

Shipped in v1.1.0