docs(vfx #C.1.5b): ship Phase C.1.5b — closes #56 + EnvCell DefaultScript dispatch

Roadmap:
- Status header now reads "Between phases" with C.1.5b in the recent-wins
  bullet list.
- New SHIPPED row in the table (C.1.5b) summarising both slices, the
  reality discovery about EnvCell statics, and the 4 visual-verified sites.
- The "IN FLIGHT — C.1.5b" sub-bullet under Phase C flipped to SHIPPED.

ISSUES.md:
- #56 removed from Active.
- #56 added to Recently closed with full commit chain (1e3c33b spec+plan,
  f3bc15e SetupPartTransforms helper, 11521f4 ParticleHookSink part-transform,
  5ca5827 activator refactor, 8735c39 GpuWorldState fire-sites), resolution
  notes, and the visual-verification record.

CLAUDE.md:
- "Currently in flight" pointer replaced by a "Currently between phases"
  marker + a C.1.5b shipped paragraph that's parallel to the existing
  C.1.5a entry.
- "After C.1.5b" → "Next phase candidates".

Visual verification 2026-05-12: portal swirl matches retail extent + lateral
spread (no ground-burial); Holtburg Inn fireplace flames; cottage chimney
smoke; spell-cast particles on +Acdream — all match retail.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -526,23 +526,43 @@ acdream's plan lives in two files committed to the repo:
   acceptance criteria. Do not drift from the spec without explicit user
   approval.
 
-**Currently in flight: Phase C.1.5b — issue #56 (per-part transforms for
-multi-emitter PES) + EnvCell static-object `DefaultScript` walker.**
-Pickup at [`docs/plans/2026-05-12-phase-c1.5b-handoff.md`](docs/plans/2026-05-12-phase-c1.5b-handoff.md).
-#56 first per the C.1.5a final reviewer — every multi-emitter PES on a
-multi-part entity (portals, chimneys, fireplaces) currently collapses
-its emitters to entity root because `ParticleHookSink` ignores
-`CreateParticleHook.PartIndex`. The mechanism is correct end-to-end;
-the part-relative transform application is the gap.
+**Currently between phases.** Phase C.1.5b just shipped; next phase is
+the user's call from the candidate list below.
+
+**Phase C.1.5b (per-part PES transforms + dat-hydrated entity DefaultScript)
+shipped 2026-05-12.** Closes issue #56. `SetupPartTransforms.Compute(setup)`
+walks `PlacementFrames[Resting]` → `[Default]` → first-available and
+returns one `Matrix4x4` per Setup part; `ParticleHookSink.SpawnFromHook`
+now transforms each `CreateParticleHook.Offset` through
+`partTransforms[PartIndex]` before applying entity rotation, so
+multi-emitter scripts distribute across mesh parts instead of collapsing
+to entity root. The `EntityScriptActivator.OnCreate` `ServerGuid==0`
+guard was relaxed: it now keys by `entity.ServerGuid` when non-zero, else
+`entity.Id` (the `0x40xxxxxx` interior-entity range is collision-free
+with server guids, so no synthetic-ID scheme is needed). `GpuWorldState`
+fires the activator from 4 new sites — `AddLandblock` +
+`AddEntitiesToExistingLandblock` (Far→Near promotion) for OnCreate,
+`RemoveLandblock` + `RemoveEntitiesFromLandblock` (Near→Far demotion)
+for OnRemove — so dat-hydrated EnvCell statics (inn fireplaces, building
+decorations) and exterior stabs (cottage chimneys) now activate their
+`Setup.DefaultScript` automatically. **Reality discovery during design
+(folded into spec §3):** EnvCell `StaticObjects` are already hydrated as
+`WorldEntity` instances by `GameWindow.BuildInteriorEntitiesForStreaming`
+with stable `entity.Id` in `0x40xxxxxx` — the handoff's §4 Q1/Q2
+(synthetic ID scheme, separate walker class) were mooted by this.
+**Visual-verified 2026-05-12** at Holtburg Town network portal (no
+ground-burial, distributed swirl), Inn fireplace flames, cottage
+chimney smoke, and a spell cast on `+Acdream`. Plan archived at
+[`docs/superpowers/plans/2026-05-13-phase-c1.5b.md`](docs/superpowers/plans/2026-05-13-phase-c1.5b.md).
 
 **Phase C.1.5a (portal PES wiring) shipped 2026-05-11** (merge `88bda12`).
 Server-spawned `WorldEntity` entities fire their `Setup.DefaultScript`
-through `PhysicsScriptRunner` on enter-world via the new ~70-line
+through `PhysicsScriptRunner` on enter-world via the
 `EntityScriptActivator` ([src/AcDream.App/Rendering/Vfx/EntityScriptActivator.cs](src/AcDream.App/Rendering/Vfx/EntityScriptActivator.cs)).
 Visual-verified at the Holtburg Town network portal: 10-hook portal
 script fires end-to-end with correct color, persistence, orientation,
-multi-emitter dispatch. Known visual gap filed as #56 (per-part
-transform handling); resolution is slice A of C.1.5b. Plan archived at
+multi-emitter dispatch. Filed #56 for per-part transform handling
+(resolved in C.1.5b above). Plan archived at
 [`docs/superpowers/plans/2026-05-12-phase-c1.5a-portals.md`](docs/superpowers/plans/2026-05-12-phase-c1.5a-portals.md).
 
 **Phase N.6 slice 1 (gpu_us fix + radius=12 perf baseline) shipped
@@ -564,7 +584,7 @@ issues closed: #52 (lifestone, `e40159f`), #54 (JobKind, `bf31e59`),
 together comprise the streaming + rendering perf foundation for the
 project.
 
-**After C.1.5b, candidate next phases (in rough preference order):**
+**Next phase candidates (in rough preference order):**
 - **Triage the chronic open-issue list** in `docs/ISSUES.md` — #2 (lightning),
   #4 (sky horizon-glow), #28 (aurora), #29 (cloud thinness), #37 (humanoid
   coat), #50 (stray tree), #41 (remote-motion blips) have been open since