feat: improve network topology — LLDP-authoritative, manual links, orphan handling (v0.11.6 Beta)

- Backend: 7-step pipeline — per-neighbor best-protocol dedup, bidirectional
  LLDP pair merging, LLDP-covered set suppression of noisy CDP/MNDP links,
  shared-segment heuristic limited to genuinely unresolved non-LLDP links
- Backend: manual_topology_links table + POST/DELETE endpoints for user-drawn connections
- Frontend: ManualEdge custom edge type (purple dashed + × delete button)
- Frontend: Connect Mode toggle — blue crosshair handles, onConnect creates DB-persisted link
- Frontend: orphan nodes in dedicated bottom row with orange warning banner
- Frontend: legend updated, canvas height increased

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

README.md

@@ -2,7 +2,7 @@
 
 A self-hosted, full-stack network management platform for MikroTik devices. Monitor, configure, and manage your entire MikroTik infrastructure — routers, switches, and wireless access points — from a single web interface.
 
-![Version](https://img.shields.io/badge/version-0.11.5_Beta-blue)
+![Version](https://img.shields.io/badge/version-0.11.6_Beta-blue)
 ![License](https://img.shields.io/badge/license-AGPLv3-blue)
 ![Docker](https://img.shields.io/badge/docker-compose-2496ED?logo=docker&logoColor=white)
 ![TypeScript](https://img.shields.io/badge/TypeScript-5.3-3178C6?logo=typescript&logoColor=white)