Add flexible post-connect command profiles

[bifrost0x]

Summary

• add explicit None, Free Text, Command, and Command Set post-connect modes with an exact execution preview
• make Command Sets the primary Commands workspace and default newly created sets to sudo disabled
• allow profiles to be created and updated independently from connecting, without storing passwords
• retain the saved-profile Pane Launcher from Show saved profiles in empty terminal panes #55, including direct key/Tailscale launch and password fallback
• validate command and Command Set ownership before rate limiting, DNS resolution, or SSH creation
• move Profiles, SSH Keys, and Jump Hosts into the account menu and add accessible guidance for the new controls
• preserve compatibility with existing Command Set and free-text startup-command profiles

Builds on #55 and addresses the workflow feedback in #48.

Validation

• python -m pytest tests -q — 303 passed, 28 skipped
• npm run test:js — 12 passed
• node --check on all 20 frontend JavaScript files
• focused combined regression suite — 169 passed, 1 skipped
• Docker build and health check successful
• running container verified to include Pane Launcher, profile auto-connect, and all post-connect modes
• clean one-commit comparison against current main
• graphify update .
• git diff --check