Add periodic encoder profiles with attachment traffic and formats, alternating A/B measurement phases, bounded Metal trace capture, and gpuprof.py log summaries. Preserve main's offline pipeline-archive integration while adding the capture build setting.
Close periodic samples at frame boundaries through the last committed shared-event fence, so every:1 reports without mixing frames or reusing an unresolved heap. Add 28 CPU checks of production profiling code and include them in CI; document the mechanism and update the symptom index.
Validated with all 31 CI-style Python test files, the profiling regression, a Mac host build, and all 133 iOS source compiles. Profiling completion and heap ownership were checked with synthetic counter/event objects; no new real-GPU or gameplay validation.
Co-authored-by: v0lumehi <aljic.zijad@gmail.com>
