docs: file #282-#284 and plan the recent-regression cleanup

Three defects introduced by the 2026-08-02/03 stabilization batch, all found
while reconciling #281's 43 test failures. Each is an instance of the weakness
the placement campaign exists to remove - two owners of one fact with no single
writer keeping them agreed - so they are cleared before C4 stacks six more
placement routes on top of them.

#282: WorldEntity.EffectCellId documents itself as existing only for outdoor
dat stabs, whose null render parent still needs retail's outdoor landcell for
CObjCell::IsInView gating; live/interior entities were explicitly meant to use
ParentCellId. f24532ad began populating it for live entities, and because
EntityEffectPoseRegistry.UpdateRoot resolves EffectCellId ?? ParentCellId it
now wins - while 12+ sites still write ParentCellId alone. Retail carries one
cell per object (CPhysicsObj::set_cell_id @0x0050f4f0, change_cell @0x00513390,
ShouldDrawParticles @0x0050fe60).

#283: 670f307c gave Runtime a world frame that rebases on the accepted teleport
Position, while App's LiveWorldOriginState rebases only after old-window
retirement completes. Between those edges the two disagree by the landblock
delta. Not yet proven reachable; the plan proves or disproves it before
restructuring anything.

#284: a placement that cannot resolve returns RetrySetupUnavailable forever
with nothing counting it or naming its reason. The fix is observability plus
fail-fast on contradictory states, never a retry cap or timeout.

Plan sequences S1 (#284) first so the other two are observable rather than
archaeological, then S2 (#282), then S3 (#283) immediately before C4 route 3,
which shares its portal code. Also records the gating change that would have
caught all of this: the complete Release suite must be green before every
commit, not a focused subset.

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

docs/ISSUES.md

@@ -24,6 +24,60 @@ What does NOT go here:
 - Every session: scan OPEN issues at start; promote/close anything we touched during the session before ending.
 - Promoting to a Phase: mark as `DONE (promoted to Phase X)` + commit SHA where the Phase entry landed.
 
+## Recent-regression cleanup — 2026-08-03
+
+Plan: [`2026-08-03-recent-regression-cleanup.md`](plans/2026-08-03-recent-regression-cleanup.md).
+All three were introduced by the 2026-08-02/03 stabilization batch, found while
+reconciling #281's 43 test failures.
+
+- **#282 — OPEN — live entities now write `EffectCellId`, contradicting its
+  documented contract, and 12 `ParentCellId` writers cannot keep it in sync.**
+  `WorldEntity.EffectCellId` (src/AcDream.Core/World/WorldEntity.cs:95-102)
+  documents itself as existing ONLY for outdoor dat stabs, which keep a null
+  render parent while retail still gives their physics object an outdoor
+  landcell for `CObjCell::IsInView` particle gating — "live/interior entities
+  normally use `ParentCellId` instead." `f24532ad` began setting it on live
+  entities at rebucket and placement projection
+  (`LiveEntityRuntime.cs:855,1101,1238`). Because
+  `EntityEffectPoseRegistry.UpdateRoot:163` resolves
+  `EffectCellId ?? ParentCellId`, the field now WINS for live entities, while
+  12+ production sites still write `ParentCellId` alone. Any of those that
+  changes cell without a matching rebucket strands particles and lights on the
+  entity's previous cell: effects vanish behind a wall the object no longer
+  occupies, or draw through one. Retail has exactly ONE cell per object
+  (`CPhysicsObj::set_cell_id` @0x0050f4f0, `change_cell` @0x00513390, read by
+  `ShouldDrawParticles` @0x0050fe60); the two-field split is our adaptation for
+  the null-render-parent stab case. Fix shape: one owner writes the entity's
+  visibility cell and the effects path reads that owner. Caught in miniature by
+  `LiveEntityLightControllerTests.Refresh_FollowsCurrentTopLevelRootAndCell`.
+- **#283 — OPEN — Runtime's world frame and App's render origin rebase at
+  different moments during a teleport.** `670f307c` gave Runtime its own world
+  frame (`RuntimePhysicsState.ObserveLocalWorldFrame`), which rebases the
+  instant an accepted Position carries `TeleportAdvanced`. App's
+  `LiveWorldOriginState` rebases only when
+  `StreamingOriginRecenterCoordinator.Advance` observes
+  `IsOriginRecenterRetirementComplete` — many frames later, after the old
+  window has fully retired. Between those two edges the two owners disagree by
+  the source-to-destination landblock delta, so a remote Create converted by
+  Runtime lands a multiple of 192 m from the geometry App is building. Same
+  failure family as the zero-offset bug `670f307c` fixed, with a wrong origin
+  instead of a missing one. NOT yet proven reachable live — the portal reveal
+  gate may or may not exclude Create during that window, and #280 says other
+  work does continue arriving through it. Two owners of one fact; the campaign
+  answer is that Runtime owns the frame and App projects it. Route-3 adjacent.
+- **#284 — OPEN — a placement that cannot resolve parks forever with no
+  diagnostic.** A first-entry placement whose world frame is absent returns
+  `RetrySetupUnavailable` (`RuntimeSetPositionState.PrepareMover:1535-1543`)
+  and is re-Advanced every pump indefinitely. Nothing counts it, names its
+  reason, or distinguishes "waiting for something that will arrive" from
+  "waiting for something that never can". This is why #281's 43 failures
+  presented as four unrelated symptoms across App and Runtime instead of one
+  cause. NOT a timeout or grace period — the fix is observability plus
+  fail-fast on genuinely unresolvable states, matching the committed-invariant
+  exception pattern established in `01f4791e`. Doing this FIRST makes #282,
+  #283, and every C4 route cheaper to diagnose and lets the connected gates
+  fail on nonzero parked entries.
+
 ## C3c placement cutover — 2026-08-02
 
 - **#276 — OPEN — SpawnPlacementSettler discards the settle's resolved

docs/plans/2026-08-03-recent-regression-cleanup.md

@@ -0,0 +1,141 @@
+# Recent-regression cleanup — plan (2026-08-03)
+
+Three defects introduced by the 2026-08-02/03 stabilization batch, found while
+reconciling the #281 test failures. All three are **ours, days old, and inside
+the least-verified code in the tree**. They are cleared before C4 resumes so
+six more placement routes are not stacked on top of them.
+
+Issues: #282 (two cell fields), #283 (two world origins), #284 (silent park).
+
+## Why these first
+
+Every one is an instance of the exact weakness the placement campaign exists to
+remove: **two owners of one fact, with no single writer keeping them agreed.**
+#282 duplicates "which cell is this in". #283 duplicates "where is zero". #284
+is why both stayed invisible. Fixing them inside C4 would mean diagnosing them
+through C4's much larger diff.
+
+## Standing discipline for this plan
+
+- Retail is the oracle. Grep `docs/research/named-retail/acclient_2013_pseudo_c.txt`
+  by `class::method` before writing.
+- Root causes only. No timeouts, grace periods, suppression flags, or
+  catch-and-ignore. #284 in particular is observability + fail-fast, never a
+  retry cap.
+- **The complete Release solution suite must be green before every commit.**
+  Focused-run-only gating is exactly what let #281–#284 ship. The full suite
+  takes about 30 seconds; there is no excuse.
+- Each fix is its own bisectable commit with root-cause evidence, and updates
+  the issue + divergence ledgers in that same commit.
+
+---
+
+## S1 — #284: make a parked placement visible (do this first)
+
+Smallest, and it turns the other two from archaeology into observation.
+
+1. Classify the park reason at the single site that produces it
+   (`RuntimeSetPositionState.PrepareMover`): awaiting collision generation,
+   awaiting Setup, awaiting world frame.
+2. Fold per-reason parked counts into the existing physics ownership snapshot
+   (`RuntimePhysicsState.CaptureOwnership`) so they appear wherever ledgers are
+   already asserted, and in the connected gates' `report.json`.
+3. Fail fast on unresolvable parks. A park awaiting the world frame *while a
+   local player is already registered* is not a wait — it is a contradiction.
+   Surface it as a committed invariant exception, the pattern `01f4791e`
+   established for receipt-ledger violations.
+4. Convergence contract: parked entries must be zero at every stable
+   checkpoint. Wire that into the lifecycle/nine-stop gate assertions.
+
+**Tests:** each park reason is reported exactly once and clears on resolution;
+the contradictory park throws rather than retrying; ledgers converge to zero.
+**Gate:** focused Runtime + complete solution suite.
+
+---
+
+## S2 — #282: one owner for an entity's visibility cell
+
+1. **Establish the retail model.** `CPhysicsObj::set_cell_id` @0x0050f4f0,
+   `change_cell` @0x00513390, `set_cell_id_recursive` @0x00510da0,
+   `ShouldDrawParticles` @0x0050fe60. Retail carries ONE cell per physics
+   object, and particle gating reads that same cell. Write the pseudocode note
+   before touching C#.
+2. **Audit the writers.** 12+ sites write `ParentCellId`
+   (`LiveEntityNetworkUpdateController` ×4, `RemotePhysicsUpdater` ×2,
+   `ProjectileController` ×3, `LiveEntityOrdinaryPhysicsUpdater`,
+   `LocalPlayerProjectionController`, `RemoteTeleportController`, …); 3 write
+   `EffectCellId`, all in `LiveEntityRuntime`. For each `ParentCellId` writer
+   record whether it also rebuckets — a rebucket with an exact cell currently
+   repairs the pair by accident. Produce the table before choosing the fix.
+3. **Decide the shape.** `EffectCellId`'s documented purpose is narrow: outdoor
+   dat stabs that keep a null render parent while retail still gives them an
+   outdoor landcell. Live/interior entities were explicitly meant to use
+   `ParentCellId`. Preferred fix, in retail's direction: live entities stop
+   populating `EffectCellId`, the stab case keeps it as the documented
+   exception, and one owner writes the visibility cell that the effects path
+   reads. If the audit shows live entities genuinely need it, the alternative
+   is a single writer that maintains both — but never 12 independent writers
+   against a field that wins.
+4. **Divergence register.** The two-field split is an adaptation from retail's
+   single cell. Add the row if none exists; delete it if step 3 collapses the
+   split.
+
+**Tests:** an entity crossing a cell boundary keeps its particles and lights
+attached; an equipped/attached child keeps its parent-relative behaviour; the
+outdoor dat stab case is unchanged.
+**Gate:** focused App + complete suite, then a **user visual check** — a
+monster with an active spell effect crossing a cell boundary, and a lit static
+object, indoors and outdoors.
+
+---
+
+## S3 — #283: one owner for the world origin
+
+Sequenced last of the three and immediately before C4 route 3, which touches
+the same portal code.
+
+1. **Prove or disprove reachability first.** With S1 landed, assert at the
+   placement site that Runtime's frame center and App's `LiveWorldOriginState`
+   center agree; run the portal/recall routes. If they never diverge in
+   practice, the fix is a permanent invariant rather than a behaviour change —
+   record that and stop. Do not restructure on a hypothesis.
+2. **Retail evidence.** How retail rebases its landblock offsets across a
+   teleport, and the ordering around `TAS_TUNNEL_CONTINUE` — the same
+   sequence #280 already needs read. Read once, use twice.
+3. **Fix shape.** Runtime owns the world frame; App projects it. Today
+   `LiveWorldOriginState` is an independent owner with its own rebase edge.
+   Make it a projection of Runtime's frame, so there is exactly one origin and
+   the retirement-driven edge becomes a *publication* of that origin rather
+   than a second decision. This is the same ownership move the campaign has
+   already applied to entities, physics, and placement.
+4. **Ordering invariant.** No placement may commit against an origin the
+   render side has not adopted. Whether that is expressed as a gate or made
+   structurally impossible falls out of step 3.
+
+**Tests:** a teleport whose old-window retirement lags by many frames cannot
+commit a placement against a mismatched origin; frame and origin rebase
+together; ordinary movement rebases neither (already pinned by
+`RuntimeWorldFrameTests`).
+**Gate:** focused + complete suite, lifecycle/reconnect, and a **user visual
+check** on repeated portal/recall arrivals with objects present.
+
+---
+
+## After S1–S3
+
+Resume the original campaign order, unchanged:
+
+1. **C4 routes 2–7** — ForcePosition, portal (with S3 landed), remote
+   Create/Position, projectile correction, drops, pickup/parent/delete.
+   Fold in #276 and #277 where their route becomes authoritative.
+2. **#280** — retail destination prefetch, landed adjacent to route 3.
+3. **C5** — delete superseded writers, complete suite, lifecycle/reconnect,
+   nine-stop soak **on the final binary**, two-client observation, the #269/#278
+   slope-glide check. Only then retire AP-1, AD-1, AP-131, and AD-60's legacy
+   half.
+4. **AP-22** — `ShadowShapeBuilder` as sole authority for authored Setup
+   collision shapes.
+5. **AD-10** — remote contact-plane projection through the real transition
+   sweep.
+6. Final movement/collision matrix; ledger, architecture, roadmap, milestones,
+   memory, `CLAUDE.md`, `AGENTS.md`. Vendor Slice 5 resumes only after that.