Added is_power_strip flag to device_models (schema migration, model,
form checkbox, DB CRUD). Power strip devices in rack view now render
a grid of plug-icon outlets instead of the regular port list, with
custom cable colors showing which outlets are in use.
- Each page template now parsed with base.html separately to avoid content block conflicts
- Connection fragments parsed standalone without base layout
- Increased SQLite max connections to 5 to prevent nested query deadlocks
- Verified connection tracing works through patch panels and wall sockets