config(vfx): default to extended particle range

Honor the requested non-dev-UI behavior by making the 2x DAT-authored particle cutoff the application default while keeping Retail as the exact opt-down setting. Update migration tests and the divergence/roadmap documentation accordingly.

Release build succeeds and all 5,857 tests pass with five intentional skips.

Co-authored-by: OpenAI Codex <codex@openai.com>

docs/architecture/retail-divergence-register.md

@@ -214,7 +214,7 @@ AP-94..AP-112 for the confirmed retail-UI completion gaps.
 
 | ~~AP-114~~ | **RETIRED 2026-07-14 (protection-effect corrective gate)** — the particle renderer no longer replaces every authored GfxObj with one bounding-box quad. Retail `Always2D` classification preserves mode-1/no-degrade full meshes through the modern shared mesh buffer and leaves only other degrade modes on the billboard path; stable emitter handles balance mesh ownership. | `src/AcDream.App/Rendering/ParticleRenderer.cs`; `RetailParticleGeometryClassifier.cs`; `particle_mesh.vert/.frag` | — | — | `CPhysicsPart::Draw @ 0x0050D7A0`; `CPhysicsPart::Always2D @ 0x0050D8A0`; `ParticleEmitter::SetInfo @ 0x0051CE90`; `docs/research/2026-07-13-retail-projectile-vfx-pseudocode.md` |
 | AP-115 | The DAT-authored portal-space viewport and its animation `SoundTweakedHook` are live, but the separate `ClientUISystem` enter/exit sound enums and centered repeating `"In Portal Space - Please Wait..."` display string are not yet presented. | `src/AcDream.App/Rendering/PortalTunnelPresentation.cs`; teleport event switch in `GameWindow.cs` | acdream has no retained cross-stack centered display-string owner or ClientUISystem sound-table-enum resolver yet; routing the line into chat or inventing direct wave IDs would be less faithful | Portal travel has the correct animated wormhole, timing, direct viewport switch, view-plane transitions, and animation-authored sound, but lacks retail's short UI cue sounds and center notice | `gmSmartBoxUI::BeginTeleportAnimation @ 0x004D6300`; `gmSmartBoxUI::UseTime @ 0x004D6E30` |
-| AP-116 | Optional Display setting `Particle Range = Extended` multiplies DAT-authored particle degradation distances by 2; default `Retail` uses exact values | `src/AcDream.UI.Abstractions/Panels/Settings/DisplaySettings.cs`; `src/AcDream.App/Rendering/Vfx/ParticleVisibilityController.cs`; `src/AcDream.Core/Vfx/ParticleSystem.cs` | Explicit opt-in for players who value distant VFX; it changes no terrain, scenery, entity, fog, or streaming distance and is reversible live | Extended can roughly enlarge the active particle area and reduce the CPU gain from MP2; distant VFX remain visible beyond retail's authored cutoff | `CPhysicsPart::GetMaxDegradeDistance @ 0x0050D510`; `GfxObjDegradeInfo::get_max_degrade_distance @ 0x0051E2D0`; `CPhysicsObj::ShouldDrawParticles @ 0x0050FE60` |
+| AP-116 | Default `Particle Range = Extended` multiplies DAT-authored particle degradation distances by 2; the `Retail` option restores exact values | `src/AcDream.UI.Abstractions/Panels/Settings/DisplaySettings.cs`; `src/AcDream.App/Rendering/Vfx/ParticleVisibilityController.cs`; `src/AcDream.Core/Vfx/ParticleSystem.cs` | User explicitly requested doubled range as the normal non-dev-UI behavior; it changes no terrain, scenery, entity, fog, or streaming distance, and remains reversible through settings | The default roughly enlarges the active particle area and reduces the CPU gain from MP2; distant VFX remain visible beyond retail's authored cutoff | `CPhysicsPart::GetMaxDegradeDistance @ 0x0050D510`; `GfxObjDegradeInfo::get_max_degrade_distance @ 0x0051E2D0`; `CPhysicsObj::ShouldDrawParticles @ 0x0050FE60` |
 | AP-117 | Outdoor particle `CLandCell::IsInView` state is reconstructed with the modern landscape renderer's per-cell frustum plus active doorway clip-plane/scissor-AABB tests; retail `LScape::landcell_check` uses `Render::get_clip_height` + `Render::block_check` on terrain-cell corner intervals | `src/AcDream.App/Rendering/TerrainModernRenderer.cs` (`CollectVisibleCells`) | The mandatory modern renderer batches terrain by landblock and has no retail `ViewIntervalType` product. Publishing cell visibility from the exact landscape draw slices preserves ownership/order and removes the former object-survivor dependency without adding a second view pipeline | At a terrain cell grazing a frustum or doorway boundary, the conservative AABB test may freeze or resume particles on a slightly different frame than retail; whole regions outside the active doorway slice are rejected, and authored distance, login/portal fail-closed behavior, and indoor PView cells remain exact | `LScape::landcell_check @ 0x005050A0`; `CLandCell::IsInView @ 0x00532CB0`; `CPhysicsObj::ShouldDrawParticles @ 0x0050FE60` |
 
 ## 4. Temporary stopgap (TS) — 33 active rows (TS-20 retired 2026-07-16 — the later named-retail audit disproved the proposed DrawingBSP polygon filter; TS-37 is a retired-row historical note, not an active count; TS-39 retired R5-V3 — sticky seams bound to the ported PositionManager/StickyManager, radii threaded; TS-45 retired 2026-07-07 — hand-rolled `SphereCollision` replaced by the faithful CSphere family port, fixing the player-vs-monster crowd wedge; TS-3 retired 2026-07-07 — `frames_stationary_fall` accounting ported in the #182 verbatim UpdateObjectInternal rebuild, fixing the airborne falling-animation wedge; TS-41 retired 2026-07-07 — SERVERVEL synth-velocity remote body-drive replaced by the retail interp catch-up + unconditional MovementManager::UseTime, the remote-creature de-overlap #184; TS-44 narrowed same day — NPC UP unified onto the interp queue, gate retained for orientation)

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

@@ -1332,7 +1332,7 @@ hitch and follows.
 | **MP-Alloc (safe batch)** | Reuse per-frame buffers: anim pose, particle draw-list, interior partition, animatedIds/drawableCells sets | ✅ SHIPPED + USER-GATED 2026-07-05 — dense-town frame-time spikes 20–87ms → 6–10ms, alloc spikes (30–75MB single-frame) eliminated, gen2 GC 5–11/window → ~0; user confirms FPS steady. 4 commits `b8c05e2b`..`91afea24` |
 | MP-Alloc (hard sites) | EnvCell settled-camera rebuild gate + physics `Transition` pooling — the residual steady ~1.6MB/frame | ⚪ OPTIONAL follow-up — would lower the median too, but the wild-swing complaint is already resolved; each needs its own careful gate (batch correctness / physics faithfulness) |
 | MP1c | Streaming cutover to pak + hitch gate (vs the 211 ms baseline) | ⚪ after MP-Alloc |
-| MP2 | Retail particle distance/cell-view degradation: DAT-authored range, exact infinite/finite off-view update branches, emitter-first render scan, optional Extended range | ✅ SHIPPED 2026-07-17 — Aerlinthe hotspot `0x32000223` resolves to retail 64m; landscape/entity streaming distance unchanged |
+| MP2 | Retail particle distance/cell-view degradation: DAT-authored range, exact infinite/finite off-view update branches, emitter-first render scan, user-requested 2× default range | ✅ SHIPPED 2026-07-17 — Aerlinthe hotspot `0x32000223` resolves to retail 64m and defaults to 128m; landscape/entity streaming distance unchanged |
 | MP3 | Arch ECS render world + delta submission (the 300-FPS lever) | ⚪ — note: does NOT fix the steady-state GC churn (that's MP-Alloc); MP3 is the draw-submission throughput lever |
 | MP4 | Zero-alloc frame loop + flat physics data (residual, post-MP-Alloc) | ⚪ hard-queued behind M1.5 #137 |
 | MP5 | Job-system parallelism | ⚪ stretch, evidence-gated |

docs/plans/2026-05-12-milestones.md

@@ -640,7 +640,8 @@ include dungeons.
   stop bookkeeping, and emitter-first render rejection. The landscape renderer
   publishes outdoor landcells independently of surviving object meshes.
   Terrain/entity streaming distance is
-  unchanged; an explicit Extended setting doubles only particle range. The
+  unchanged; the user-requested default Extended setting doubles only particle
+  range, while Retail remains available as the exact cutoff. The
   final two-client visual gate is still pending.
 - **L.1c local attack receive path (implemented and live-gated 2026-07-15)** —
   local non-autonomous mt-0 UpdateMotion now uses retail's wholesale interpreted

docs/research/2026-07-17-retail-particle-visibility-pseudocode.md

@@ -172,5 +172,6 @@ does not change landscape, scenery, entity, or fog distance.
   Login and portal-space frames publish an empty world view; explicit
   examination and dedicated-pass policies are the only bypasses.
 - The renderer filters an emitter before scanning its particle slots.
-- Default mode uses authored retail distances. The optional Extended setting is
+- The user-requested default Extended mode doubles authored retail distances.
-  an explicit user-facing adaptation and is recorded in the divergence register.
+  Exact Retail remains selectable; the default adaptation is recorded in the
+  divergence register.

src/AcDream.UI.Abstractions/Panels/Settings/DisplaySettings.cs

@@ -5,8 +5,8 @@ namespace AcDream.UI.Abstractions.Panels.Settings;
 
 /// <summary>
 /// Particle visibility distance policy. Retail uses the GfxObj-authored
-/// distance exactly; Extended is an explicit acdream adaptation for players
+/// distance exactly; Extended is the acdream default requested for longer
-/// who prefer longer-lived distant effects with the corresponding CPU cost.
+/// distant-effect visibility, with the corresponding CPU cost.
 /// </summary>
 public enum ParticleRange
 {
@@ -49,7 +49,7 @@ public sealed record DisplaySettings(
         Gamma:        1.0f,
         ShowFps:      false,
         Quality:      QualityPreset.High,
-        ParticleRange: ParticleRange.Retail);
+        ParticleRange: ParticleRange.Extended);
 
     /// <summary>16:9 resolution presets offered in the dropdown.</summary>
     public static IReadOnlyList<string> AvailableResolutions { get; } = new[]

src/AcDream.UI.Abstractions/Panels/Settings/SettingsPanel.cs

@@ -238,7 +238,7 @@ public sealed class SettingsPanel : IPanel
 
         int particleRangeIndex = (int)d.ParticleRange;
         if (particleRangeIndex < 0 || particleRangeIndex >= s_particleRangeNames.Length)
-            particleRangeIndex = (int)ParticleRange.Retail;
+            particleRangeIndex = (int)DisplaySettings.Default.ParticleRange;
         if (renderer.Combo("Particle Range", ref particleRangeIndex, s_particleRangeNames))
             _vm.SetDisplay(d with { ParticleRange = (ParticleRange)particleRangeIndex });
 
@@ -248,8 +248,8 @@ public sealed class SettingsPanel : IPanel
             + "preview live as you drag; Cancel reverts to the saved value. "
             + "Quality preset applies streaming radius, anisotropic, and A2C "
             + "immediately on Save; MSAA sample count requires a restart. "
-            + "Particle Range defaults to retail-authored distances; Extended "
+            + "Particle Range defaults to Extended, which doubles authored "
-            + "doubles effect range and costs additional CPU time.");
+            + "effect distance; Retail restores the exact client cutoff.");
     }
 
     /// <summary>

tests/AcDream.UI.Abstractions.Tests/Panels/Settings/SettingsStoreTests.cs

@@ -84,11 +84,11 @@ public sealed class SettingsStoreTests : System.IDisposable
         Assert.Equal(DisplaySettings.Default.Fullscreen, loaded.Fullscreen);
         Assert.Equal(DisplaySettings.Default.VSync, loaded.VSync);
         Assert.Equal(DisplaySettings.Default.FieldOfView, loaded.FieldOfView);
-        Assert.Equal(ParticleRange.Retail, loaded.ParticleRange);
+        Assert.Equal(ParticleRange.Extended, loaded.ParticleRange);
     }
 
     [Fact]
-    public void LoadDisplay_invalid_particle_range_falls_back_to_retail()
+    public void LoadDisplay_invalid_particle_range_falls_back_to_default()
     {
         File.WriteAllText(_tempPath, """
             {
@@ -99,11 +99,11 @@ public sealed class SettingsStoreTests : System.IDisposable
 
         var loaded = new SettingsStore(_tempPath).LoadDisplay();
 
-        Assert.Equal(ParticleRange.Retail, loaded.ParticleRange);
+        Assert.Equal(ParticleRange.Extended, loaded.ParticleRange);
     }
 
     [Fact]
-    public void LoadDisplay_numeric_undefined_particle_range_falls_back_to_retail()
+    public void LoadDisplay_numeric_undefined_particle_range_falls_back_to_default()
     {
         File.WriteAllText(_tempPath, """
             {
@@ -114,7 +114,7 @@ public sealed class SettingsStoreTests : System.IDisposable
 
         var loaded = new SettingsStore(_tempPath).LoadDisplay();
 
-        Assert.Equal(ParticleRange.Retail, loaded.ParticleRange);
+        Assert.Equal(ParticleRange.Extended, loaded.ParticleRange);
     }
 
     [Fact]