Allow changing temperature of running instance (IPC/signal support) #75
Description
Currently, changing the temperature requires killing the running hyprsunset process and starting a new one. This causes a brief flicker (screen goes to default colors before new filter applies) because hyprsunset doesn't allow two instances (A CTM manager is already running).
Request: Add a way to change temperature/gamma of a running instance, e.g.:
- hyprsunset --set-temp 3000 that communicates with running instance
- Signal-based (e.g. SIGUSR1 to reload from config)
- hyprctl integration
This would enable flicker-free transitions for scripts like automatic day/night temperature adjustment.