Add remote SSH repository management and tmux integration

[randomradio]

Summary

• add remote SSH host profiles, remote repository onboarding, and endpoint-aware remote execution
• integrate native SSH and tmux flows for remote session discovery, attach, creation, and reselection reuse
• fix follow-up regressions around Canvas focus restoration, terminal scrollback preservation, and deferred focus stealing from active text inputs

Testing

• make build-app
• make install-dev-build

Notes

• Remote execution uses native ssh and tmux commands
• Full test runs are still affected by unrelated pre-existing test-target compiler issues in the repo

[madJohnZhang]

哎 我刚好也在做这个东西 没权限push结果发现了这个