fix(render): foliage wind keys on the DAT-classified WeatherKind, not the day-group index (Campaign VM VM6)

FoliageWindByDayGroup / FoliageWindDayGroupPoint(int ActiveDayGroup, ...)
becomes FoliageWindByWeather / FoliageWindWeatherPoint(string WeatherKind,
...) in AtmospherePolicyDeclaration (Plugin.Abstractions is BCL-only, so
the key is the exact member name of AcDream.Core.World.WeatherKind rather
than the enum itself). The raw activeDayGroup index carries no weather
meaning by itself; WeatherState.cs already classifies each day group's
authored DAT name into one of five real weather kinds, and that fact was
already threaded through AtmosphericFrameInputs.Weather / uAtmosphereWeather.x
— this reuses it instead of guessing an index-to-category mapping.

Built-in table (BuiltInAtmosphericRenderPack.AtmospherePolicy()): Clear
0.25/0.15, Overcast 0.60/0.35, Rain 0.85/0.60, Snow 0.35/0.20, Storm
1.00/0.75 — all five WeatherKind members declared, the invented "Cloudy"
row dropped. RenderPackAtmospherePolicyEvaluation.FoliageWind now takes a
WeatherKind and matches by weather.ToString() (ordinal) against each
declared point's name; a kind absent from the table falls back to the
declared Clear row, then to (0,0) if Clear itself is undeclared. The
delta-seconds EMA interpolation (EaseTowardTarget) is unchanged.
AtmosphericPostProcessGraph.ResolveFoliageWind and its two callers
(RenderPostProcess via inputs.Weather; RenderDirectionalShadows via
foundation.Atmosphere.Kind) now pass WeatherKind instead of the day-group
int.

RenderPackValidation.ValidateAtmosphere (runs for every pack declaring an
AtmospherePolicy, not gated to Tier2/shadow packs) now rejects an unknown
or non-exact-case weather-kind name and a repeated kind, mirroring the
existing ActiveDayGroupMultiplier duplicate-key check.

Tests: RenderPackAtmospherePolicyEvaluationTests rewritten for the
kind-keyed API (all five kinds resolve to their declared row, an unlisted
kind falls back to Clear, ordinal exact-case matching, null-table
handling); RenderPackSpirvValidatorTests gains four descriptor-validation
cases (unknown name, wrong case, duplicate kind, the five-kind table
accepted); AtmosphericPostProcessGraphTests' three foliage-wind cases now
select WeatherKind.Storm via `with` instead of an assumed day-group index.

Spot-check (per the coordinator's ask, not changed here): yes —
ActiveDayGroupMultiplier / EvaluateDayGroupPolicy (pre-existing, Campaign
AR/VM3-era — BuiltInAtmosphericRenderPack.AtmospherePolicy()'s three rows
`new ActiveDayGroupMultiplier(0, 1.0), (1, 0.35), (2, 0.20)`) key the
sun-ray/shadow/volumetric day-group strength multiplier by the same raw
activeDayGroup index with an undocumented assumed meaning (0=brightest ...
2=dimmest), the identical class of issue this commit fixes for foliage
wind. Left unchanged per instruction; flagging for the coordinator to file.

Full solution Debug and Release builds green. App hermetic filter
6024/6026 — the same 2 pre-existing failures as VM6a/VM6b. Both were
re-run in isolation per the verification ask: both still fail alone (not
a load-flake in this environment) — confirmed via git stash earlier this
session that both already fail on the unmodified pre-VM6 baseline, so
they are pre-existing and unrelated to this change. Core.Tests hermetic
4697/4697. RenderPackValidator.Tests 30/30. No shader/spv changes in this
commit (pure C#/docs fix).

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

docs/architecture/retail-divergence-register.md

@@ -37,7 +37,7 @@ accepted-divergence entries (#96, #49, #50).
 
 ---
 
-## 1. Intentional architecture (IA) — 22 active rows (IA-25 filed 2026-08-22 for Campaign VM VM6's opt-in weather-driven foliage wind — a render-only vertex displacement with no authored retail wind direction to read; IA-24 filed 2026-08-22 for Campaign AR's opt-in real-time sun/moon directional shadows; IA-23 filed 2026-08-17 at the night-round review fix round (F8) — the House tab's not-yet-expired purchase-restriction line renders .NET's culture-default `DateTime.ToString()` where retail renders the C runtime's `strftime("%c", localtime(...))`, a different formatting engine producing a different-shaped (but equivalent-intent) date string; IA-22 filed 2026-08-13 — the #391 user-directed modern-only curated resolution list + desktop-mode default, replacing retail's full adapter enumeration + authored 800x600 default)
+## 1. Intentional architecture (IA) — 22 active rows (IA-25 filed 2026-08-22 for Campaign VM VM6's opt-in weather-driven foliage wind — a render-only vertex displacement keyed by the DAT-classified `WeatherKind`, not the raw day-group index, with no authored retail wind direction to read; IA-24 filed 2026-08-22 for Campaign AR's opt-in real-time sun/moon directional shadows; IA-23 filed 2026-08-17 at the night-round review fix round (F8) — the House tab's not-yet-expired purchase-restriction line renders .NET's culture-default `DateTime.ToString()` where retail renders the C runtime's `strftime("%c", localtime(...))`, a different formatting engine producing a different-shaped (but equivalent-intent) date string; IA-22 filed 2026-08-13 — the #391 user-directed modern-only curated resolution list + desktop-mode default, replacing retail's full adapter enumeration + authored 800x600 default)
 
 | # | Divergence | Where (file:line) | Why it is safe / justified | Risk if assumption breaks | Retail oracle |
 |---|---|---|---|---|---|
@@ -62,7 +62,7 @@ accepted-divergence entries (#96, #49, #50).
 | IA-22 | **Filed 2026-08-13 (#391, user-directed: "we should only support modern resolutions. Not any old format").** The Config Resolution dropdown offers a CURATED list — the monitor's real mode enumeration filtered to modern widescreen families (16:9/16:10/21:9/32:9, ≥1280 wide, fitting the desktop; `DisplayModeCatalog.Curate`) — and its Defaults value is the desktop's own mode. Retail offered the adapter's complete enumeration including 4:3 legacy modes and authored `800x600` as the row default (`gmConfigUI::InitOptions SetDefaultValue(0x03200258)`; `gmClient::Init @0x004047af` `Device::ForceDisplayResolution(1, 0x320, 0x258)`). | `src/AcDream.App/Rendering/DisplayModeCatalog.cs`; `src/AcDream.App/UI/Layout/ConfigOptionsPageController.cs` (Resolution row); fixture fallback `src/AcDream.UI.Abstractions/Panels/Settings/DisplaySettings.cs` (`AvailableResolutions`, 800x600 removed) | Explicit product direction. **Amended 2026-08-16 (#407, Campaign CC gate round 1):** the dropdown now offers `DisplayModeCatalog.WindowedResolutions` — the curated hardware modes UNIONed with the static modern-ladder sizes that fit the desktop — because a WINDOWED pick is a plain Size write needing no video mode, and remote/RDP virtual displays advertise almost no modes (the live RDP display exposed only 1920x1080 + the 2056x1290 desktop, starving the dropdown). The original "an offered mode is supported by construction" invariant now holds for the FULLSCREEN half only: the fullscreen apply still validates against the hardware `Resolutions` list plus `GlfwDisplayModeSwitcher`'s monitor-mode-list hard guard, so a fullscreen pick of a windowed-only entry refuses safely (log-and-stay, #388; the #392 apply-result seam is that family's open follow-up) — "Graphics mode not supported" crashes remain unreachable from the dropdown. | A user wanting a genuine legacy 4:3 mode cannot pick it; retail-parity comparisons of the Config tab's list/default will show the deviation. | decomp sites in the Divergence column; ISSUES #391 |
 | IA-23 | **Filed 2026-08-17 at the night-round review fix round (F8).** `gmHouseUI::DisplayPurchaseTimeText @0x004a3110`'s not-yet-expired branch renders `"You may buy another landscape house at " + strftime("%c", localtime(timestamp + 0x278d00)) + ". This restriction does not apply to apartments."` — byte-decoded from raw pushed literals at `@0x004a3265`/`@0x004a321d`/`@0x004a3235` (all three text pieces confirmed; a prior filing had wrongly called this "unrecoverable"). This port renders the SAME three pieces, in the same order, with the same expiry-timestamp math, but formats the middle date/time piece with .NET's culture-default `DateTime.ToString()` (no explicit format string) rather than the C runtime's `strftime("%c", ...)` — the two engines do not share a format table, so the RENDERED SHAPE of the date/time differs (e.g. .NET's short numeric date+time vs the CRT's `Ddd Mon DD HH:MM:SS YYYY`-style locale string) even though both express "the process's own locale's full date+time" and use the SAME underlying instant (local time, matching retail's `localtime()`). | `src/AcDream.Runtime/Gameplay/RuntimeHouseState.cs` (`Recompute`'s not-expired branch) | Both are "whatever the process locale says" full date+time strings; no game-logic reads or parses this text back, it is pure chat-scroll presentation, so a differently-shaped (but equally legible) date string carries no functional risk | A retail-side-by-side visual comparison will show a differently formatted date/time (not a byte-identical `strftime("%c")` reproduction) — cosmetic only | `gmHouseUI::DisplayPurchaseTimeText @0x004a3110`; `strftime`/`localtime` CRT calls at `@0x004a322c`/`@0x004a3216` |
 | IA-24 | **Filed 2026-08-22, Campaign AR.** An explicitly selected atmospheric render pack adds cascaded real-time directional shadows from terrain, trees, buildings, players, monsters, and other retained outdoor casters. The one shadow direction follows the visible authored sun, then the dominant haloed moon (`0x01001F6A`), then the secondary moon (`0x01001F67`); a moon supplies direction only while colour/energy remains retail's single interpolated `SkyTimeOfDay.DirColor × DirBright` channel. Retail renders none of these real-time object-shadow maps and does not expose a second moon light. | `src/AcDream.App/Rendering/Packs/AuthoredCelestialShadowSource.cs`; `src/AcDream.App/Rendering/DirectionalSunShadowRenderer.cs`; pack-only receiver shaders; evidence `docs/research/2026-08-22-dereth-celestial-shadow-sources.md` | This is the user-requested headline graphics enhancement and is strictly opt-in. The retail path remains the default and authoritative fallback; pack-off does not build/select shadow work or change `SceneLighting`. One selected source reuses one cascade array, so moon support does not multiply shadow resources. | Pack-on output intentionally differs from retail. A wrong celestial identity/transform or stale source transition would visibly misalign shadows from the sky; pack-off output changing would violate the campaign's primary safety contract. | `SkyDesc::GetLighting @0x00500A80`; `GameSky::UseTime @0x005075B0`; installed Region `0x13000000`; cited research note |
-| IA-25 | **Filed 2026-08-22, Campaign VM VM6.** An explicitly selected atmospheric render pack sways procedural-scenery foliage (trees/bushes — entity ids in the `0x8XXYYIII` `ProceduralSceneryIdAllocator` namespace) in `mesh_atmospheric.vert` and the four `directional_shadow_world_*` caster vertex shaders, driven by a weather-table lean/branch/flutter vertex displacement (`foliage_wind.glsl`, `FoliageWindModel` CPU mirror) whose mean/gust strength is looked up per active day group and eases toward its target over `WeatherSystem.TransitionSeconds` (10 s) so a weather change never snaps. Retail's fixed-function renderer applies no per-vertex wind displacement to any scenery mesh — Dereth's trees are static geometry. Wind direction (`wind-direction-degrees`, default 225°) is a plain pack default: there is no authored retail wind direction to read (no wind data exists in retail at all). Render-only: `WorldPicker` picks the undisplaced mesh, so a swaying leaf can be up to `lean + branch` metres from its pick volume at the moment of a click; foliage subsets are cosmetic scenery, not interactable in retail either. | `src/AcDream.App/Rendering/Shaders/foliage_wind.glsl`; `src/AcDream.App/Rendering/Wb/FoliageWindClassification.cs`; `src/AcDream.App/Rendering/Packs/FoliageWindModel.cs`; `src/AcDream.App/Rendering/Packs/AtmosphericPostProcessGraph.cs` (`ResolveFoliageWind`); `src/AcDream.App/Rendering/Packs/BuiltInAtmosphericRenderPack.cs` (wind settings + `FoliageWindByDayGroup`) | Explicitly opt-in graphics enhancement — the retail path (`mesh_modern`, `terrain_modern`, `mesh_detail`) never reads `BatchData.flags` bits 1/2 and is pixel-identical with the pack off. The classification never touches Runtime/Core physics — the collision BSP is the trunk, and picking against the undisplaced mesh has no gameplay consequence since foliage is not interactable. | Pack-on output intentionally differs from retail (moving foliage where retail has none). A wrong classification bit would sway a non-foliage object or leave a real tree still; a caster/receiver clock or amplitude mismatch would visibly misalign a leaf's shadow from the leaf itself. Pack-off output changing would violate the campaign's primary safety contract. | None — retail applies no vertex wind displacement to any geometry; `ProceduralSceneryIdAllocator` (bit 31 entity-id namespace, existing acdream mechanism, not retail) |
+| IA-25 | **Filed 2026-08-22, Campaign VM VM6.** An explicitly selected atmospheric render pack sways procedural-scenery foliage (trees/bushes — entity ids in the `0x8XXYYIII` `ProceduralSceneryIdAllocator` namespace) in `mesh_atmospheric.vert` and the four `directional_shadow_world_*` caster vertex shaders, driven by a weather-table lean/branch/flutter vertex displacement (`foliage_wind.glsl`, `FoliageWindModel` CPU mirror) whose mean/gust strength is looked up per DAT-classified `AcDream.Core.World.WeatherKind` (Clear/Overcast/Rain/Snow/Storm — the same classification `WeatherState.cs` already derives from the active day group's authored name, not the day group's raw index, which carries no weather meaning by itself) and eases toward its target over `WeatherSystem.TransitionSeconds` (10 s) so a weather change never snaps. Retail's fixed-function renderer applies no per-vertex wind displacement to any scenery mesh — Dereth's trees are static geometry. Wind direction (`wind-direction-degrees`, default 225°) is a plain pack default: there is no authored retail wind direction to read (no wind data exists in retail at all). Render-only: `WorldPicker` picks the undisplaced mesh, so a swaying leaf can be up to `lean + branch` metres from its pick volume at the moment of a click; foliage subsets are cosmetic scenery, not interactable in retail either. | `src/AcDream.App/Rendering/Shaders/foliage_wind.glsl`; `src/AcDream.App/Rendering/Wb/FoliageWindClassification.cs`; `src/AcDream.App/Rendering/Packs/FoliageWindModel.cs`; `src/AcDream.App/Rendering/Packs/AtmosphericPostProcessGraph.cs` (`ResolveFoliageWind`); `src/AcDream.App/Rendering/Packs/BuiltInAtmosphericRenderPack.cs` (wind settings + `FoliageWindByWeather`) | Explicitly opt-in graphics enhancement — the retail path (`mesh_modern`, `terrain_modern`, `mesh_detail`) never reads `BatchData.flags` bits 1/2 and is pixel-identical with the pack off. The classification never touches Runtime/Core physics — the collision BSP is the trunk, and picking against the undisplaced mesh has no gameplay consequence since foliage is not interactable. | Pack-on output intentionally differs from retail (moving foliage where retail has none). A wrong classification bit would sway a non-foliage object or leave a real tree still; a caster/receiver clock or amplitude mismatch would visibly misalign a leaf's shadow from the leaf itself. Pack-off output changing would violate the campaign's primary safety contract. | None — retail applies no vertex wind displacement to any geometry; `ProceduralSceneryIdAllocator` (bit 31 entity-id namespace, existing acdream mechanism, not retail) |
 
 ---
 

docs/plans/2026-08-22-visualmaster-campaign.md

@@ -474,18 +474,26 @@ direction to read, and the register row says so.
 
 ### VM6 outcome (implementation landed 2026-08-22; owner visual gate outstanding)
 
-Two commits (VM6a shader ABI v2 plumbing, VM6b the feature) shipped the exact
-design above. Settings (`BuiltInAtmosphericRenderPack.Settings()`):
-`wind-enabled` (bool, default on), `wind-strength` (0–2×, default 1.0),
-`wind-direction-degrees` (0–360°, default 225 — no authored retail wind
-direction exists to read), `wind-lean-metres` (default 0.25),
-`wind-branch-metres` (default 0.15), `wind-flutter-metres` (default 0.05,
-forced to 0 on the Low preset), `wind-canopy-height-metres` (default 8). The
-Clear/Cloudy/Overcast/Rainy mean/gust rows live in
-`AtmospherePolicyDeclaration.FoliageWindByDayGroup`, keyed by the SAME
-day-group index convention `ActiveDayGroupMultipliers` already established
-two lines above it in `AtmosphericPolicy()` (0 Clear / 1 Cloudy / 2 Overcast;
-index 3 Rainy is new). Classification bits live in
+Two commits (VM6a shader ABI v2 plumbing, VM6b the feature) shipped the
+design above; a same-day fix-round commit corrected the weather-table key.
+Settings (`BuiltInAtmosphericRenderPack.Settings()`): `wind-enabled` (bool,
+default on), `wind-strength` (0–2×, default 1.0), `wind-direction-degrees`
+(0–360°, default 225 — no authored retail wind direction exists to read),
+`wind-lean-metres` (default 0.25), `wind-branch-metres` (default 0.15),
+`wind-flutter-metres` (default 0.05, forced to 0 on the Low preset),
+`wind-canopy-height-metres` (default 8). The mean/gust rows live in
+`AtmospherePolicyDeclaration.FoliageWindByWeather`, keyed by NAME
+(`FoliageWindWeatherPoint.WeatherKind`, an exact ordinal match against
+`AcDream.Core.World.WeatherKind`'s member names — `Clear` 0.25/0.15,
+`Overcast` 0.60/0.35, `Rain` 0.85/0.60, `Snow` 0.35/0.20, `Storm` 1.00/0.75),
+not the raw `activeDayGroup` index the original design used: the index
+carries no weather meaning by itself, and `WeatherState.cs` already
+classifies each day group's authored DAT name into one of these five real
+kinds — the same fact `AtmosphericFrameInputs.Weather` /
+`uAtmosphereWeather.x` already threads through the frame, reused here
+instead of re-guessed. `RenderPackAtmospherePolicyEvaluation.FoliageWind`
+matches by `weather.ToString()` and falls back to the declared Clear row for
+an unlisted kind. Classification bits live in
 `FoliageWindClassification` (`AcDream.App.Rendering.Wb`): bit 1 (`0x2`)
 cutout foliage, bit 2 (`0x4`) trunk, computed once per (entity, subset) in
 `WbDrawDispatcher.ClassifyBatches` (world receiver) and