fix: SSH import issues - key paths, SSL/color case, useSSHConfig

[datlechin]

Summary

Fixes several bugs in the foreign app connection importers that caused imported SSH connections to fail:

• Bare SSH key filenames (e.g. id_ed25519) now resolved to ~/.ssh/id_ed25519
• useSSHConfig changed from false to true (matches default) so ~/.ssh/config is read for host/key resolution
• SSL mode "required" corrected to "Required" to match SSLMode raw values (was silently disabling SSL)
• Color strings corrected from lowercase to title-case to match ConnectionColor raw values (was silently dropping colors)
• Port parsing handles both Int and String types in TablePlus and Sequel Ace plists

Test plan

• Import a TablePlus connection with SSH key auth, connect immediately without editing
• Verify imported SSL connections show SSL enabled (not silently disabled)
• Verify imported connection colors are preserved
• All importer tests pass