EffectHost gains self_at (the layer's source + masks + first N effects at
another layer time) and layer_at (another layer at another comp time);
EffectEnv carries the effect's stack index. The renderer serves these via
Renderer::layer_input, cached in the layer cache under input keys (footage
included, keyed by source time) with a depth guard against recursion.
Time effects are TIME_DEPENDENT so processed-layer keys fold in layer
time; layers with time effects and expressions are not cached.
Also registers the Effect > Audio specs (DSP in effects::audio_fx; the
mixdown integration follows in M11.2). Audio effects are skipped by the
video effect pass.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
