Scaffold homelab-monitor: Fastify API + React dashboard + CI

Vertical slice for Phase 1 (v1-dashboard milestone): Proxmox collector,
SQLite storage, local auth, and a dashboard UI showing host/container
status cards. Config-driven collector registry so future data sources
(SSH-based hosts, Zabbix, network discovery) plug in without rewiring.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,12 @@
+node_modules/
+dist/
+data/
+*.db
+*.db-journal
+*.db-wal
+*.db-shm
+.env
+.env.*
+!.env.example
+*.log
+.DS_Store