Improve Docker temperature monitoring documentation for clarity (related to #600)

Updated the Quick Start for Docker section in TEMPERATURE_MONITORING.md to be
more user-friendly and address common setup issues:

- Added clear explanation of why the proxy is needed (containers can't access hardware)
- Provided concrete IP example instead of placeholder
- Showed full docker-compose.yml context with proper YAML structure
- Added sudo to commands where needed
- Updated docker-compose commands to v2 syntax with note about v1
- Expanded verification steps with clearer success indicators
- Added reminder to check container name in verification commands

These improvements should help users who encounter blank temperature displays
due to missing proxy installation or bind mount configuration.

docs/INSTALL.md

@@ -23,6 +23,19 @@ Pulse protects the initial Quick Security Setup screen with a one-time bootstrap
 | Docker container | `/data/.bootstrap_token` inside the container or the mounted host volume |
 | Helm / Kubernetes | The persistent volume mounted at `/data` |
 
+**For Proxmox Quick Install (LXC):**
+The installer creates an LXC container, so the token is inside the container, not on the PVE host. Use one of these commands from your Proxmox host:
+```bash
+# Enter the container interactively
+pct enter <ctid>
+cat /etc/pulse/.bootstrap_token
+
+# Or retrieve token directly
+pct exec <ctid> -- cat /etc/pulse/.bootstrap_token
+```
+The installer displays the container ID when installation completes.
+
+**For other deployments:**
 1. SSH to the host (or `docker exec` into the container).
 2. Display the token: `cat /etc/pulse/.bootstrap_token` (adjust the path per the table).
 3. When the UI prompts for setup, paste the token into the dialog or send it as the `X-Setup-Token` header for API calls.