Fix docker-compose.yml temperature proxy bind mount configuration

This corrects several issues with the temperature proxy configuration
in the example docker-compose.yml:

Issues fixed:
1. **Wrong mount path**: Was using /mnt/pulse-proxy (LXC path) instead of
   /run/pulse-sensor-proxy (Docker path). While the client auto-detects both
   paths, this was inconsistent with documentation.

2. **Wrong permissions**: Was mounted as :ro (read-only) but needs :rw
   (read-write) for the Unix socket to work properly.

3. **Enabled by default**: Would cause container startup issues if the
   proxy wasn't installed on the host.

Changes:
- Commented out the bind mount by default (requires manual setup)
- Changed path from /mnt/pulse-proxy to /run/pulse-sensor-proxy
- Changed permissions from :ro to :rw
- Added clear comment explaining it requires setup with --standalone flag
- Points users to documentation

Now matches the documented Docker setup process and won't break
fresh installations where the proxy isn't installed yet.

docker-compose.yml

@@ -9,8 +9,9 @@ services:
       - "${PULSE_PORT:-7655}:7655"
     volumes:
       - pulse-data:/data
-      # Secure temperature monitoring via host-side proxy
-      - /mnt/pulse-proxy:/mnt/pulse-proxy:ro
+      # Secure temperature monitoring via host-side proxy (requires setup - see docs)
+      # Uncomment after installing pulse-sensor-proxy on host with --standalone flag
+      # - /run/pulse-sensor-proxy:/run/pulse-sensor-proxy:rw
     environment:
       - TZ=${TZ:-UTC}
     healthcheck: