Discovery: show import apply result summary

[BadgerOps]

Follow-up to #187 and PR #188.

Summary

Show a structured result summary after discovery import apply.

Why

PR #188 applies selected imports and returns item-level outcomes, but operators need a clearer post-apply summary for bulk workflows.

Scope

• Add result counts for imported, linked-only, skipped, blocked, conflicts, created records, and linked records.
• Surface the summary in the Discovery UI after apply.
• Link from the summary to the merged network view filtered to affected resources where feasible.
• Keep item-level details available for troubleshooting.

Acceptance Criteria

• Bulk import apply returns and displays clear aggregate counts.
• The user can tell which resources were imported, linked-only, skipped, or blocked.
• Tests cover mixed-result apply responses.