fix: Mermaid diagram syntax + deploy-tuning.sh path + fleet quick fixes

Mermaid diagrams fixed for Gitea rendering:
- Replaced all <br/> → <br> (86 tags across 4 docs)
- Replaced Unicode chars with ASCII (em dash, multiply, middle dot, star)
- Fixed invalid bidirectional dotted arrow in NETWORK-TOPOLOGY.md
  (<--. "..." .--> is not valid Mermaid; replaced with two -.-> arrows)
- Simplified node labels for cleaner rendering

Host fixes applied (live, not in repo — documented here for audit trail):
- SSH keys standardized to exactly 2 approved keys on all 7 hosts
  (removed host-generated RSA keys, added missing VP TechOps key to tsys9)
- Packages installed: iperf3 (tsys9), sysstat (tsys5), nvme-cli (tsys4/5),
  net-tools (tsys1/6/7)
- tsys4 tuning: rmem/wmem 16MB→128MB, netdev_max_backlog 5000→250000,
  tcp_max_syn_backlog 1024→2048, tuned profile→network-throughput
- tsys5: nconnect options added to storage.cfg (3 NFS stanzas patched;
  will apply on next Proxmox NFS remount/reboot)
- noatime applied to root fs on tsys4 + tsys5 (was only tsys5)
- tsys1 lldpd: installed but systemd/dbus issue prevents enabling
  ("Transport endpoint is not connected") — needs investigation/reboot

Bug fix: deploy-tuning.sh computed wrong script path (scripts/ vs
perf/scripts/) — fixed to use dirname/scripts/apply-tunings.sh

💘 Generated with Crush

Assisted-by: Crush:glm-5.2

perf/deploy-tuning.sh

@@ -4,7 +4,7 @@
 # Default mode is dry-run. Pass --apply to commit. Pass --no-nfs to skip NFS section.
 set -uo pipefail
 
-SCRIPT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)/scripts/apply-tunings.sh"
+SCRIPT="$(cd "$(dirname "${BASH_SOURCE[0]}")/scripts" && pwd)/apply-tunings.sh"
 SSH_OPTS=(-o BatchMode=yes -o ConnectTimeout=8 -o ServerAliveInterval=10 -o StrictHostKeyChecking=accept-new)
 MODE=""
 EXTRA_FLAGS=""