perf #418: publish landblocks under the meter, not one per streaming tick

Phase-1 measurement (new [publish-timing]/[stream-tick] probe surfaces,
ACDREAM_PROBE_REVEAL_TIMING=1) refuted the ~31 ms-per-admission
hypothesis: the hold runs at ~64 fps with the streaming tick at ~32 Hz,
the whole 625-block window costs only ~500 ms of publication CPU (far
blocks ~0.17 ms, near 2-43 ms), and steady state showed ZERO meter
yields with ~0.22 ms of the 2 ms budget used - yet exactly one block
published per tick against a ~400-deep completion queue.

The real limiter: Runtime's collision-generation activation is a
deliberate two-poll transaction (the first
TryAcquireCollisionPrefixMutationPermission poll parks residents and
refuses by design), and LandblockPresentationPipeline.Advance's metered
arm returned Completed=false on ANY nonterminal commit, which
DrainAndApply treats as end-of-frame. One landblock per 32 Hz tick =
the flat 32/s, with the authored budget ~90% idle.

Fix: the metered arm now uses the same Runtime-owned gate the unmetered
arm and the synchronous CompletePublication API always used
(CanContinueMutationSynchronously). The second poll runs in the same
frame under the same meter, so the unchanged 2 ms elapsed-time ceiling
is now genuinely the authoritative per-frame bound; with any real debt
(live residents parked mid-game, pending withdrawals, dispatch backlog)
publication defers to the next frame exactly as before. No budget
values change, no reveal-gate/readiness change, and the streamed result
is byte-identical - only the frame scheduling of identical operations.

Measured A/B (this binary, two runs): totalMs 12689 / 12734 vs baseline
26728/27395/27503; loaded slope 32/s -> bursts of 100-360/s, 625/625 in
~6-7 s vs ~23 s. The remaining ~12.7 s floor is fully attributed in
docs/ISSUES.md: ~8 s of real budgeted readiness work plus retail's
authored tunnel exit (TunnelContinue 2-5 s + two 1 s fades, golden
constants), so the <12 s acceptance needs a lead decision on the
hold-time budget, not another hidden limiter.

New regression pin:
MeteredLoaded_NonterminalCommitWithoutDebt_CompletesInOneMeteredAdvance.
Gates: Release build 0 errors; App tests 5576/3 skips/0 failed;
Runtime tests 1756/0.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/AcDream.App/Streaming/RevealTimingProbe.cs

@@ -47,6 +47,7 @@ internal sealed class RevealTimingProbe
     private long _gateReadyMs = -1;
     private long _materializedMs = -1;
     private long _lastProgressMs;
+    private int _framesSinceProgress;
 
     public RevealTimingProbe(Func<int>? loadedLandblockCount) =>
         _loadedLandblockCount = loadedLandblockCount;
@@ -88,6 +89,7 @@ internal sealed class RevealTimingProbe
         if (_generation == 0 || portal.Generation != _generation)
             return;
 
+        _framesSinceProgress++;
         long elapsed = _clock.ElapsedMilliseconds;
         if (!_render && readiness.IsRenderNeighborhoodReady)
         {
@@ -136,13 +138,21 @@ internal sealed class RevealTimingProbe
         if (!_summarized && elapsed - _lastProgressMs >= 1000)
         {
             _lastProgressMs = elapsed;
+            // #418: frames = render frames observed since the previous
+            // progress line (the hold's effective frame rate). The paired
+            // [stream-tick] line carries the same window's streaming-tick
+            // wall clock, meter operation/yield/admission counts, backlogs,
+            // and the reasons the meter refused work.
             Console.WriteLine(
                 $"[reveal-timing] elapsedMs={elapsed} "
                 + $"render={(_render ? 1 : 0)} "
                 + $"composites={(_composites ? 1 : 0)} "
                 + $"collision={(_collision ? 1 : 0)} "
                 + $"loaded={_loadedLandblockCount?.Invoke() ?? -1}"
-                + $"/{_windowLandblocks}");
+                + $"/{_windowLandblocks} "
+                + $"frames={_framesSinceProgress}");
+            PublicationTimingProbe.EmitStreamingTickWindow();
+            _framesSinceProgress = 0;
         }
     }