docs: mark Phase N.1 shipped + file road-edge tree as known issue

Adds Phase N.1 to "Phases already shipped" table at top of roadmap,
updates the Phase N section to mark N.1 with checkmark SHIPPED status,
and files the known road-edge-tree cosmetic difference at landblock
0xA9B1 in ISSUES.md as issue #50 follow-up.

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

docs/ISSUES.md

@@ -46,6 +46,50 @@ Copy this block when adding a new issue:
 
 # Active issues
 
+## #50 — Road-edge tree at 0xA9B1 visible in acdream but not retail
+
+**Status:** OPEN
+**Severity:** LOW (cosmetic; one spawned tree near the road in Holtburg)
+**Filed:** 2026-05-08
+**Component:** scenery placement / Phase N (WorldBuilder rendering migration)
+
+**Description:** With `ACDREAM_USE_WB_SCENERY=1` (default since commit `b84ecbd`),
+a tree at landblock 0xA9B1 around `(lx=85.08, ly=190.97)` appears in acdream but
+neither retail nor ACME WorldBuilder render it. Upstream Chorizite/WorldBuilder
+DOES render it, so our migration to WB's helpers (Phase N.1) inherited this
+discrepancy from upstream.
+
+**Root cause (suspected):** ACME WorldBuilder includes a per-vertex road check that
+skips the entire vertex when its road bit is set (see
+`references/WorldBuilder-ACME-Edition/WorldBuilder/Editors/Landscape/GameScene.cs:1074`).
+The current vertex (4,8) has a road bit set in the dat. ACME skips it;
+Chorizite/WorldBuilder doesn't; we don't.
+
+**Fix attempt that didn't work:** commit `e279c46` added the per-vertex road check
+directly to our `GenerateViaWb` (and legacy `Generate` for parity). It successfully
+removed the offending tree but over-suppressed scenery in other landblocks (visual
+regressions during user testing). Reverted in commit `677a726`. ACME's check likely
+interacts with other factors (per-vertex building check, or something else in ACME's
+pipeline) that we'd need to port together, not the road check alone.
+
+**Next steps:**
+1. Investigate ACME's full per-vertex filter set (road + building + anything else)
+   and port them as a coherent unit, not piecemeal.
+2. OR upstream the per-vertex road check to Chorizite/WorldBuilder (which is now our
+   submodule fork) so it lands as a generic ACME-conformance improvement.
+3. OR consider switching fork target from Chorizite/WorldBuilder to ACME WorldBuilder
+   for future phases (N.2+).
+
+Visually undetectable to most users; one extra tree at one landblock. Defer until
+other Phase N work catches a similar issue and a coherent fix becomes obvious.
+
+**Files:**
+- `src/AcDream.Core/World/SceneryGenerator.cs` — `GenerateInternal` is the active path
+- `src/AcDream.Core/World/WbSceneryAdapter.cs` — adapter used by `GenerateInternal`
+- `references/WorldBuilder-ACME-Edition/WorldBuilder/Editors/Landscape/GameScene.cs:1074` — ACME's per-vertex road filter
+
+---
+
 ## #49 — Scenery (X, Y) placement drifts from retail at some landblocks
 
 **Status:** OPEN

docs/plans/2026-04-11-roadmap.md

@@ -57,6 +57,7 @@
 | K | Input architecture — `Action` enum, `KeyChord`, `KeyBindings`, multicast `InputDispatcher` with scope-stack + modal capture, retail-default keymap (152 bindings), `keybinds.json` persistence, F11 Settings panel with click-to-rebind + conflict detection, main menu bar + View menu | Live ✓ |
 | L.0 | Full retail-style Settings interface — F11 tabbed panel with 6 tabs (Keybinds + Display + Audio + Gameplay + Chat + Character). `settings.json` at `%LOCALAPPDATA%\acdream\`, per-toon `Character` keying (swapped on EnterWorld). Display GL knobs (Resolution / Fullscreen / VSync / FOV / ShowFps) + Audio (Master / SFX) live-wired; Gameplay / Chat / Character settings persist for server-sync wiring later. Tab API extension to `IPanelRenderer`; chat Copy mode (read-only multi-line); per-panel layout reset; FramebufferResize handler keeps GL viewport + camera aspect + panel positions in sync. | Live ✓ |
 | C.1 | PES particle system + sky-pass refinements — retail-faithful `ParticleEmitterInfo` unpack with all 13 motion integrators (`Particle::Init`/`Update` ports of `0x0051c290`/`0x0051c930`), `PhysicsScriptRunner` with `CallPES` self-loop semantics, `ParticleHookSink` with `EmitterDied` cleanup, instanced billboard `ParticleRenderer` with material-derived blend (DAT emitters never default additive — pulled from particle GfxObj surface), global back-to-front sort, BC clipmap alpha-keying, AttachLocal `is_parent_local=1` live-parent follow via `UpdateEmitterAnchor`. Sky pass: `Translucent+ClipMap` → alpha-blend cloud sheet (matches `D3DPolyRender::SetSurface` `0x0059c4d0`), raw-`Additive` fog-skip (matches `0x0059c882`), per-keyframe `SkyObjectReplace` Translucency/Luminosity/MaxBright divide-by-100, bit `0x01` pre/post-scene split (matches `GameSky::CreateDeletePhysicsObjects` `0x005073c0`), Setup-backed (`0x020xxxxx`) sky objects via `SetupMesh.Flatten`, persistent GL sampler objects (Wrap + ClampToEdge) replace per-frame wrap-mode mutation (ported from WorldBuilder's `OpenGLGraphicsDevice`), post-scene Z-offset gated on `(Properties & 4) != 0 && (Properties & 8) == 0` per `GameSky::UpdatePosition` `0x00506dd0`. Sky-PES playback disabled by default (named-retail proves `GameSky` drops `pes_id`); `ACDREAM_ENABLE_SKY_PES=1` opens the experimental path. 1325 → 1331 tests. | Live ✓ |
+| N.1 | WorldBuilder-backed scenery (Chorizite/WorldBuilder fork as submodule, SceneryHelpers + TerrainUtils replace our inline ports) | Live ✓ |
 
 Plus polish that doesn't get its own phase number:
 - FlyCamera default speed lowered + Shift-to-boost
@@ -532,12 +533,16 @@ for our deletions/additions; merge upstream `master` periodically.
 **Sub-phases (strangler-fig with feature flags):**
 
 - **N.0 — Setup.** Submodule + project references + build green. ~1-2 hrs.
-- **N.1 — Scenery algorithm calls.** Replace `IsOnRoad` /
-  `DisplaceObject` / slope-normal calc / rotation / scale inside
-  `SceneryGenerator.Generate()` with calls to WB's `SceneryHelpers` +
-  `TerrainUtils`. Tiny adapter `LandBlock → TerrainEntry[]`. Keeps our
-  data flow + `ScenerySpawn` shape. Feature flag
-  `ACDREAM_USE_WB_SCENERY=1`. ~1-2 days.
+- **✓ SHIPPED — N.1 — Scenery algorithm calls.** Shipped 2026-05-08.
+  Replaced `IsOnRoad` / `DisplaceObject` / slope-normal calc / rotation /
+  scale inside `SceneryGenerator.Generate()` with calls to WB's
+  `SceneryHelpers` + `TerrainUtils`. Adapter `WbSceneryAdapter` produces
+  `TerrainEntry[]`. Visual verification at Holtburg confirmed Issue #49's
+  previously missing edge-vertex trees still visible after the migration;
+  rotation bug fixed (our retail port's `yawDeg = -(450-degrees)%360`
+  formula was ~180° off from retail's actual `Frame::set_heading` atan2
+  round-trip). One known cosmetic difference filed in ISSUES.md
+  (road-edge tree at landblock 0xA9B1).
 - **N.2 — Terrain math helpers.** Refactor `TerrainSurface.SampleZ` /
   `SampleNormal` / `SampleSurface` to call WB's `TerrainUtils.GetHeight`
   / `GetNormal` internally. ~1-2 days.