Reorganize repo: one folder per application under apps/.

Move docker/ and configs/ into apps/<name>/ with config/ subfolders.
Proxmox split into hosts/pve and hosts/dell-proxmox. Nginx under
infrastructure/. Update sync script, RESTORE.md, and per-app READMEs.

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/proxmox/hosts/dell-proxmox/qemu-server/103.conf

@@ -0,0 +1,18 @@
+agent: 1
+boot: order=sata0
+cores: 1
+cpu: x86-64-v2-AES
+ide2: none,media=cdrom
+memory: 2048
+meta: creation-qemu=9.2.0,ctime=1747652143
+name: Synology
+net1: virtio=BC:24:11:79:5C:AE,bridge=vmbr1,firewall=1
+numa: 0
+ostype: l26
+sata0: local-lvm:vm-103-disk-0,size=3572M
+sata1: local-lvm:vm-103-disk-1,size=250G
+scsihw: virtio-scsi-single
+smbios1: uuid=1e47e76c-af8a-4a27-8ec8-21a5fe6a6d10
+sockets: 2
+tags: prive
+vmgenid: 70c61ac7-e12d-4a77-b5fe-810ff7f79f4e