(engine) correct blend_image opacity clamping direction

(engine) tighten conductor deadline calculation in adaptive mode

(doc) update target_displayhint.lua @outargs return type

(engine) SIMD-accelerate dirty rect accumulation pass

(engine) fix off-by-one in event queue capacity check

(doc) fix image_surface_properties return table field names

(engine) optimize video object pool iteration in arcan_video.c

(doc) correct target_input.lua @inargs parameter order

(net) vectorize a12 chacha20 block function in a12.c

(shmif) add test coverage for signal/event round-trip

(build) clean up optimization flags, unify LTO and sanitizer interaction

(engine) wire up subsystem profiling counters in conductor and trace

(engine) audit hot paths in arcan_video for SIMD opportunities

(test) scaffold benchmark harness under tests/benchmark

(build) add profile-guided optimization build targets