Experimental: Group 1: 675nm LLLT + RPT

Single direct in-contact pencil probe, wavelength 675 nm, power 30 mW. Irradiance 222 mW/cm², fluence 6.7 J/cm², spot size 0.9 cm². Delivered in continuous and pulsed (2.5 Hz) modes, 6 Joules for 30 sec per treatment point (lymphatic chain, sub-occipital musculature, facet joints, nerve root exits, trigger points). Administered 3× weekly for 6 weeks (30 min/session).~Device: Omega XP Model, Omega Laser Systems (UK) Class II therapeutic photobiomodulation device. Equipped with single direct in-contact pencil probes (675 nm, 30 mW; 820 nm, 200 mW) and a 46-cluster LED probe (mixed diodes 660-950 nm). Operates in continuous and pulsed (2.5 Hz) modes. Spot size 0.9-10 cm², irradiance 95-222 mW/cm², fluence 6.7-11.4 J/cm². CE-certified for therapeutic use; applied in this trial for cervicogenic headache management.

Experimental: Group 2: 820nm LLLT + RPT

Single direct in-contact pencil probe, wavelength 820 nm, power 200 mW. Irradiance 222 mW/cm², fluence 6.7 J/cm², spot size 0.9 cm². Delivered in continuous and pulsed (2.5 Hz) modes, 6 Joules for 30 sec per treatment point (same anatomical sites as Group 1). Administered 3× weekly for 6 weeks (30 min/session).~Device: Omega XP Model, Omega Laser Systems (UK) Class II therapeutic photobiomodulation device. Equipped with single direct in-contact pencil probes (675 nm, 30 mW; 820 nm, 200 mW) and a 46-cluster LED probe (mixed diodes 660-950 nm). Operates in continuous and pulsed (2.5 Hz) modes. Spot size 0.9-10 cm², irradiance 95-222 mW/cm², fluence 6.7-11.4 J/cm². CE-certified for therapeutic use; applied in this trial for cervicogenic headache management.

Experimental: Group 3: 46 Cluster LED Probe + RPT

46-cluster LED probe combining 660 nm, 950 nm, 870 nm, 880 nm, 940 nm, 820 nm. Irradiance 95 mW/cm², fluence 11.4 J/cm², spot size 10 cm². Delivered in continuous and pulsed (2.5 Hz) modes, 114 Joules for 120 sec per treatment area (same anatomical sites as above). Administered 3× weekly for 6 weeks (30 min/session).~Device: Omega XP Model, Omega Laser Systems (UK) Class II therapeutic photobiomodulation device. Equipped with single direct in-contact pencil probes (675 nm, 30 mW; 820 nm, 200 mW) and a 46-cluster LED probe (mixed diodes 660-950 nm). Operates in continuous and pulsed (2.5 Hz) modes. Spot size 0.9-10 cm², irradiance 95-222 mW/cm², fluence 6.7-11.4 J/cm². CE-certified for therapeutic use; applied in this trial for cervicogenic headache management.