Fix: barrel fuse shows its blast radius + burns ~1.5s (was 0.6s)

Operator feel report: the explosion radius was unreadable and the fuse
too short to react to. Two changes:

- Tuning.BarrelFuseTicks 36 -> 90 (~1.5s): long enough to READ the
  danger and walk out, and better for baiting enemies onto a lit
  barrel.
- WorldFeedbackSystem draws a pulsing ground DISC at exactly
  Tuning.BarrelExplodeRadius under every lit fuse (keyed on the same
  replicated Remaining=0-on-a-live-barrel cue as the boom split; one
  shared pulsing material; removed via the existing prune path).

Verified live: disc appeared 0.07s after the pop (first fuse
snapshot), persisted to the boom at 1.54s, scale read exactly 3.25 =
the true detonation radius; 470/470 EditMode; console clean.

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

Assets/_Project/Scripts/Simulation/Tuning.cs

@@ -109,9 +109,10 @@ namespace ProjectM.Simulation
 
         // ---- Exploding barrels (Phase 1.5 hazard; server-only detonation consts — see Exploding_Barrels_Build_Spec) ----
 
-        /// <summary>Fuse ticks between the pop (Remaining hits 0) and detonation (~0.6 s @60): long enough for the
-        /// popper to step out + for the replicated Remaining=0 to straddle snapshots (the client's fuse cue).</summary>
-        public const uint BarrelFuseTicks = 36;
+        /// <summary>Fuse ticks between the pop (Remaining hits 0) and detonation (~1.5 s @60; operator feel call
+        /// 07-10 — the 0.6 s fuse popped before the danger could be read): long enough to READ the blast-radius
+        /// disc + walk out, and for the replicated Remaining=0 to straddle snapshots (the client's fuse cue).</summary>
+        public const uint BarrelFuseTicks = 90;
 
         /// <summary>Detonation radius (world units, XZ). Above melee reach so point-blank pops are punished, but a
         /// fuse-length walk clears it comfortably.</summary>