feat: add DeepSeek and NVIDIA NIM providers

- Add deepseek and nvidia entries to gateway-provider config

- Add DEEPSEEK_API_KEY and NVIDIA_API_KEY to .env.example

- Add deepseek and nvidia to doctor's LLM provider check

- Fix remaining harness-log → log-message reference

infrastructure/passepartout.service

@@ -0,0 +1,15 @@
+[Unit]
+Description=Passepartout Daemon
+Documentation=https://github.com/amrgharbeia/opencortex
+After=network.target
+
+[Service]
+Type=simple
+User=%u
+ExecStart=%h/projects/opencortex/passepartout daemon
+Restart=on-failure
+RestartSec=10
+WorkingDirectory=%h/projects/opencortex
+
+[Install]
+WantedBy=default.target