Add merge mode for bash import

[studiowebux]

Summary

• Merge checkbox in Paste Commands modal: when checked, imported commands are deep-merged with existing editor YAML instead of replacing it
• Zone merge: arrays (services, ports, sources, etc.) concatenated and deduplicated; scalars (target, forward, masquerade) from imported config overwrite
• Direct merge: chains, rules, passthroughs concatenated and deduplicated; rule_groups from existing preserved
• Variables and other top-level keys from existing YAML preserved through merge
• When existing YAML is invalid, falls through to replace mode
• When Merge is unchecked, behavior is unchanged (full replace)

Test plan

• Empty editor + import = same result as replace mode
• Existing config + import new zone = both zones present
• Existing config + import overlapping services = no duplicates
• Existing config with variables/loops + merge = variables preserved in output
• Merge unchecked = replace behavior unchanged
• Invalid existing YAML + merge checked = falls back to replace

🤖 Generated with Claude Code