[reveal-timing] lines from the reveal coordinator: per-dimension
first-ready edges (render neighborhood, composite textures, collision,
gate, materialization), 1 Hz progress with the resident-landblock count
(new GpuWorldState.LoadedLandblockCount), and one SUMMARY line at the
viewport reveal. Measurement-first groundwork for the login-load speedup:
the readiness barrier observes its dimensions serially, so the edges give
each dimension's observed tail while the progress lines expose the
pacing shape (a budget-paced linear drip reads directly off the counts).
Probe-gated in StreamingDiagnostics per Code Structure Rules §5; no
behavior change, one branch per Evaluate poll when unset.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
