Override the framework's canSee answer for a specific
(target, detail) pair. raw is what the framework computed
from perceivedBand against the detail-level threshold. The
shadow can yes/no the answer outright. Identity default: raw.
Per-viewer vision profile (scotopic minimum, photopic maximum,
band shift). Identity default: null — caller falls back to
the framework's default human-shaped profile. The Organism
subsystem will populate this from species data later via a
shadow that reads the species template's vision parameters.
Modulate the perceived light band at a location. raw is the
band the framework has already computed (with size scale and
vision profile applied). Identity default: raw. A
BlindfoldShadow returns 'pitch-black'. A magical-light
shadow could shift it up.
Public shape provided by PerceptionMixin. Each seam returns the raw answer unchanged in the default identity implementation; Shadows override to modulate.