Added Connect Mode toggle button on rack and device views. When active,
clicking a port selects it (glowing accent border), clicking a second
port opens a mini form to choose connection type/color/labels and
create the cable in one flow. Escape or re-clicking deselects. Port
elements now use onclick JS instead of HTMX triggers to support both
normal inspection mode and connect mode.
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.