feat(composer): Tier 4c -- a season that can actually ship, with a veto page

The composer could invent, measure and show strates. What did not exist was
an ARTEFACT a season could ship. Now it does.

VF_ComposeSeason: generate N candidates -> measure -> reject failures ->
select a descent sequence -> emit a JSON manifest + a review page.

⭐ THE PROPERTY THAT MATTERS: round-trip bit-identity. The manifest was
loaded, every selected stack rebuilt, and 393,216 density samples compared
BIT-IDENTICALLY. Re-composing the same seed yields byte-identical JSON.
A manifest that cannot reproduce its own world is worthless, and that is
the one thing that could not be assumed. Floats serialise as readable
values PLUS exact IEEE bits, so a season survives a text round trip.

Test season: 24 generated, 19 survived the hard gates, 6 selected.
18 not selected -- 4 vacuous, 1 primordial-law failure, 13 policy
non-selections. 4 grounded, 2 outliers. EVERY selected slot passes the
primordial law, asserted per slot rather than sampled.

Selection policy is explicit, named and PROVISIONAL, because Jahni has not
defined "good" yet and said so: "it'll be easier once i'm able to see the
strates candidates." So no quality score was invented and presented as
settled. The knobs are 75/25 grounded-to-outlier (outlier axis = distance
from corpus centroid), adjacent-similarity threshold .20 with penalty 1.0,
new-archetype bonus .10, new-recipe bonus .05, boss cadence every 5th
non-terminal slot. All of them are his to turn.

The veto is a review page in DESCENT ORDER -- the season read top to bottom
the way it is played, not the survivor/outlier ordering the candidate sheet
uses. Reuses VoxelStratePreview rather than a second renderer.

  Saved/VoxelForge/SeasonTest/season_0000_seed_9320/season_manifest.json
  .../review/index.html

⚠️ FIVE GAPS CODEX RAISED, recorded not buried:
1. §4's Tier A is strates PLUS passages; only the strate spine is persisted.
   Manager-generated passage geometry and content placement are not.
2. Authored fixed strates keep scalar vectors + asset paths, not every
   asset-level passage/biome/disturbance/content field.
3. Boss slots are MARKERS, not arena or content guarantees.
4. WorldRadiusVoxels == 0 is enforced as specced but contradicts a
   production bounded world -- Jahni's call, still unset by design.
5. Bit identity is proven for the same build and platform. A frozen season
   spanning engine versions needs an explicit schema contract. Real risk,
   since seasons freeze generation for months.

Build clean, 28 succeeded / 0 failed, verified by me.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VJiTcTSDNkKBtnNdiBtdaU

CODEMAP.md

@@ -523,6 +523,21 @@ the caller centres it on each coarse survivor's `LargestComponentPoint` and the
 sheet remains sorted by survivor status then descending corpus-centroid distance, repeats exact measurement
 windows, marks rejection reasons, explains the 2D-connectivity limitation, and has no runtime generation hook.
 
+**`Public/VoxelSeasonManifest.h` + `Private/VoxelSeasonManifest.cpp`** — Tier 4c's offline season
+artifact. `VF_ComposeSeason` generates a bounded configurable candidate batch, applies the Tier 2
+non-vacuous / largest-component / primordial-law gates, then selects an ordered Tier A spine with the
+explicit provisional grounded/outlier, adjacency, variety, and five-slot boss policy. The JSON stores
+the complete six-family parameter vector (float values carry both a readable number and exact IEEE-754
+bits), seed/index/archetype/recipe, bounds, measured metrics, gate facts, candidate audit, and rejection
+counts. `VF_LoadVoxelSeasonManifest` plus `VF_RebuildVoxelSeasonStrate` are the round-trip seam; generated
+recipe entries rebuild through the mandatory-post builder, while authored `FixedStrates` retain their
+absolute slot and native vector. The selected-only descent review reuses `VoxelStratePreview`, and all
+composition/review work is editor/build-box code; normal runtime generation is untouched. The focused
+season test currently reports **24 generated / 19 hard-gate survivors / 6 selected / 18 unselected or
+rejected**, with **4 vacuous**, **1 primordial-law budget**, **13 policy-not-selected**, and **393,216**
+round-trip density samples bit-identical. The specified UE 5.7 editor build succeeded and the full
+`VoxelForge` namespace passed **28/28 tests** after this seam was added.
+
 ### 3.9 Player edits — `Public/VoxelDiffLayer.h` + `.cpp`
 `UVoxelDiffLayer : UObject` (h:77). Stores `FVoxelModification` (h:43: Center/Radius/Strength;
 **negative Strength = carve, positive = fill**) grouped by chunk in `TMap ChunkMods`.
@@ -590,6 +605,7 @@ The plugin's first tests (`OPSTACK-PLAN.md` Phase 0.5). Run them from the editor
 | ″ | `VoxelForge.Composer.TerrainDetailLiveness` | Fixed 4,096-point `GetDensityAt` lattice, legacy and operator-stack paths; changes one terrain-detail group at a time with an empty terrain-op pool. Proves 9 live groups / 23 fields and 3 dead groups / 11 fields; all 24 rows match. |
 | `VoxelForgeComposerPromotionTest.cpp` | `VoxelForge.Composer.Promotion` | Re-measures the 12 project/default members, simulates five deterministic 24-candidate seasons with normalized measured-metric novelty (`<0.20`), cap 6, cumulative JSON promotion, provenance counts, corpus-hash checks, fresh-load gate verification, spread/survival reporting, and deliberate stale-metric corruption. Final run: **9 promoted**, corpus **4/8/9**, survival **20.8/54.2/54.2/45.8/50.0%**, spread **0.869214→0.916302**, **63.556 s**, 0 failures. |
 | `VoxelForgeComposerStructureRollTest.cpp` | `VoxelForge.Composer.StructureRoll` | Rolls root polarity → legal shape source → polarity-derived conversion → 4–8 declaration-legal modifiers → mandatory structural posts; blends the six native parameter families independently, measures 64 novel stacks, captures the same grid for the deterministic filled/contour XZ/XY preview, runs a separate step-1 radius-64 ROI pass for the 42 survivors centred on `LargestComponentPoint`, checks exact arrival→departure connectivity, rerolls every recipe/stack for determinism, and brute-forces every uniform box verdict. Final run: **42/64 survival (65.6%)**, **64 distinct recipes**, **0 invalid recipes**, **64 coarse filled + 64 coarse contour pairs**, **42 fine filled + 42 fine contour pairs**, blank plan/card **6/42→3/42**, **243.649 s**, **0 refusals**. |
+| `VoxelForgeComposerSeasonTest.cpp` | `VoxelForge.Composer.Season` | Composes a six-slot offline season from 24 structure candidates; asserts **19 hard-gate survivors**, **6 selected**, deterministic byte-identical JSON, absolute descent order, all selected primordial-law facts, and a selected-only review page with metrics/reasons/boss markers. Loads the JSON, rebuilds every selected stack, and compares **393,216** bounded density samples bit-for-bit. Rejection audit: **4 vacuous**, **1 primordial-law budget**, **13 policy-not-selected**. |
 | `VoxelForgeComposerCorpusFreeTest.cpp` | `VoxelForge.Composer.CorpusFree` | Shares each structure recipe across today's corpus blend, naive independent uniform rolls, and constraint-sampled rolls. The completed equal-arm run uses **16 candidates per arm** (256×3 and 64×3 were stopped before aggregate output for runtime), step 4 / radius 256 / `MaxCells=8,000,000`, fixed passage-law mouths, and 40 box probes per candidate. Result: **13/16, 7/16, 7/16** survival; survivor walkable means **0.066071, 0.012566, 0.012851** and feature-scale means **92.307693, 64.571426, 31.428572**. Box checks: **196/260,876**, **310/412,610**, **262/348,722** proved/voxels, **0 violations** in every arm. |
 | `VoxelForgeLayoutOrderIndependenceTest.cpp` | `VoxelForge.Determinism.LayoutOrderIndependence` | Builds a known transient soft-pointer pool, then rebuilds it in original, reversed, and swapped orders. Requires a non-empty layout and passage set, and compares every slot's definition/Z/height plus passage endpoints, radius, type, control geometry, and bounds bit-for-bit. |
 | `VoxelForgePassageOpenSpaceTest.cpp` | `VoxelForge.Determinism.PassageLandsInOpenSpace` | Uses the real fixture density path to check every generated inter-strate passage whose destination query answers: a 16-point ring outside the mouth's carve/blend band has at least half its samples in destination air, and the endpoint matches the pure open-point result within the mouth's float envelope. This is a connectivity proxy, not a flood-fill proof. Reports checked passages and false/unanswerable archetypes; fails if it inspects zero passages. |

COMPOSER-NOTES.md

@@ -89,6 +89,64 @@ normal game path.** The editor-only PIE inspection button described below is a d
 exception: it overlays one already-built slot so the owner can walk a measured candidate; it is not
 cooked, does not compose a season, and is cleared by RebuildStrates.
 
+**Tier 4c is now the build-box seam:** `VF_ComposeSeason(SeasonSeed, Settings)` generates a bounded
+candidate batch, measures every candidate, rejects vacuous/fragmented/primordial-law failures, and
+writes the selected Tier A spine as diffable `season_manifest.json`. The default test budget is 24
+candidates at measurement step 8 and a six-slot output; production can raise the candidate count for
+the overnight budget without changing the runtime contract. The manifest stores each selected seed,
+recipe, complete native parameter-family vector, archetype, bounds, measured metrics, and gate facts.
+Floating-point fields carry both a readable value and their exact IEEE-754 bit pattern, so a loader can
+rebuild the same stack and the season test can assert bit-identical density rather than assume it.
+
+The selected-only review page is a descent-ordered `VoxelStratePreview` contact sheet. Each card shows
+the depth, recipe, metrics, grounded/outlier/fixed selection reason, and boss-slot marker. Selection is
+deliberately provisional: the current readable policy reserves 75% grounded and 25% outlier slots,
+penalises near-identical neighbours, rewards new archetypes/recipes, and respects fixed absolute slots.
+Jahni's preview and veto remain the decision that turns this artifact into a published season. The
+composer and review writer are editor/build-box code only; no normal runtime generation path calls
+them, and `WorldRadiusVoxels` remains 0.
+
+An abbreviated manifest shape is:
+
+```json
+{
+  "format": "VoxelForgeSeasonManifest",
+  "schema_version": 1,
+  "season": 0,
+  "seed": 9320,
+  "candidate_count": 24,
+  "survivor_count": 19,
+  "selected_count": 6,
+  "strates": [
+    {
+      "depth_index": 0,
+      "seed": 123,
+      "archetype": "Maze",
+      "uses_recipe": true,
+      "recipe": {
+        "root_polarity": 0,
+        "root": { "op_class": 0, "param_block": 3 },
+        "shape_source": { "op_class": 3, "param_block": 3 },
+        "conversion": { "op_class": 8, "param_block": 3 },
+        "structural_param_block": 3,
+        "modifiers": []
+      },
+      "parameters": { "maze": { "LatticeSpacing": { "value": 18.0, "bits": "0x41900000" } } },
+      "measured_metrics": {
+        "air_fraction": { "kind": "float", "value": 0.5, "bits": "0x3F000000" },
+        "largest_component_share": { "kind": "float", "value": 0.9, "bits": "0x3F666666" }
+      },
+      "selection_reason": "grounded; provisional 75/25 policy",
+      "boss_slot": false
+    }
+  ]
+}
+```
+
+The real file is complete; the sample is intentionally abbreviated. `FVoxelSeasonFixedStrate` also
+allows a build invocation to provide a full recipe/vector for an absolute slot, while entries adapted
+from today's authored `FixedStrates` retain their native vector and source asset path.
+
 ### 3.2 Structure: how a stack gets assembled
 
 The current shipping builders, for reference (structural posts included; TunnelNetwork's builder is
@@ -759,8 +817,15 @@ reviewable outlier quota instead of assuming survivor promotion preserves surpri
 ### ⭐ It is TWO things, not one
 
 **Tier A — the SPINE. Finite, tiny, actually stored.** Strate slots and passages. ~30 strates plus a few
-passages each is roughly 100 entries — kilobytes. **This already exists** as `StrateLayout` plus the
-passage list, computed once in `UVoxelStrateManager::Initialize`.
+passages each is roughly 100 entries — kilobytes. The runtime manager already computes `StrateLayout`
+and its passage list once in `UVoxelStrateManager::Initialize`; Tier 4c now adds the first reviewable
+serialized Tier A artifact, `season_manifest.json`, containing the selected ordered strate spine and
+the data required to reproduce each selected density field exactly.
+
+The current Tier 4c manifest deliberately serializes the chosen strates, not the manager's generated
+inter-strate passage geometry or the full material/creature/content placement payload. The season test
+therefore proves each stored strate's density round trip; passage serialization and the wider content
+manifest remain a follow-up before this file can be called the complete world manifest described here.
 
 **Tier B — the FIELD. Effectively unbounded in XY, therefore NEVER stored.** Landmarks, rooms, material
 deposits, build sites. It is a **function**: give it a region, it enumerates what is there.
@@ -1038,8 +1103,16 @@ roughness and should stay late in the stack.
   violations, plus 64 rendered preview pairs and an index.html contact sheet. The fine survivor ROI
   is centred on `LargestComponentPoint` and labelled largest open space; the final before/after
   blank-plan count is 6/42 → 3/42.
-- ⬜ Reject-and-resample driven by Tier 2 (§3.5) · the **offline season pipeline** with Jahni's review
-  and veto (§3.1).
+- ✅ **Season pipeline (§3.1, §3.5, §4, Tier 4c)** — `VF_ComposeSeason` generates and measures a
+  bounded candidate batch, rejects vacuous/fragmented/primordial-law failures, and writes a Tier A
+  JSON spine plus a selected-only descent review page using `VoxelStratePreview`. The explicit policy
+  is provisional: default 75% grounded / 25% outlier, adjacent-similarity penalty, archetype/recipe
+  variety bonuses, and fixed absolute slots with boss markers every five non-terminal slots. The
+  focused artifact run was **24 generated / 19 hard-gate survivors / 6 selected / 18 rejected or
+  unselected**: 4 vacuous, 1 primordial-law budget failure, and 13 policy-not-selected. The loader
+  rebuild test compared **393,216 density samples bit-identically**, and the same seed emitted
+  byte-identical JSON. This closes the offline artifact and veto seam; full passage/content manifest
+  serialization is still open as noted in §4.
 
 ### Tier 5 — the long game
 - ✅ **Promotion** (good strates rejoin the corpus) — JSON promotable records and season manifests,
@@ -1145,6 +1218,17 @@ in §3.3. The StructureRoll preview measured fine blank plan/card counts **6/42
 42 fine filled pairs plus 42 contour pairs with 0 refusals. No existing generation/equivalence test
 failed.
 
+**2026-09-05 — Tier 4c season validation.** The specified UE 5.7 `VoxelMEditor Win64 Development`
+build succeeded after adding the season manifest and review seam. The focused
+`VoxelForge.Composer.Season` test passed, then the full headless `VoxelForge` namespace reported
+**28 succeeded, 0 failed, 0 not run, 0 succeeded-with-warnings**. The season artifact used 24
+generated candidates, 19 hard-gate survivors, and selected 6; it recorded 4 vacuous rejections, 1
+primordial-law budget rejection, and 13 provisional-policy non-selections. Reloading the JSON and
+rebuilding every selected stack compared **393,216 density samples bit-identically**; composing the
+same seed twice emitted byte-identical JSON. The selected-only descent review was written beside the
+manifest. The run also kept all existing equivalence, determinism, box-verdict, and connectivity
+tests green.
+
 ---
 
 ## 11. Tier 1 status — passages aim at real open space (bounded full-point query; build not run)

Source/VoxelForge/Private/Tests/VoxelForgeComposerSeasonTest.cpp

@@ -0,0 +1,208 @@
+// Tier 4c — offline season composition, manifest determinism, and exact rebuild.
+
+#if WITH_DEV_AUTOMATION_TESTS && WITH_EDITOR
+
+#include "Misc/AutomationTest.h"
+#include "Misc/FileHelper.h"
+#include "Misc/Paths.h"
+
+#include "VoxelDensityOpStack.h"
+#include "VoxelSeasonManifest.h"
+#include "VoxelStrateComposer.h"
+
+namespace
+{
+    bool SameDensityBits(float A, float B)
+    {
+        return FMemory::Memcmp(&A, &B, sizeof(float)) == 0;
+    }
+}
+
+IMPLEMENT_SIMPLE_AUTOMATION_TEST(
+    FVoxelForgeComposerSeasonTest,
+    "VoxelForge.Composer.Season",
+    EAutomationTestFlags::EditorContext | EAutomationTestFlags::EngineFilter)
+
+bool FVoxelForgeComposerSeasonTest::RunTest(const FString& Parameters)
+{
+    (void)Parameters;
+
+    FVoxelStrateCorpus Corpus;
+    FString CorpusReport;
+    TestTrue(TEXT("season test loads a valid corpus"),
+             Corpus.LoadFromAssetRegistry(CorpusReport) && Corpus.IsValid());
+    if (!Corpus.IsValid())
+    {
+        AddError(CorpusReport);
+        return false;
+    }
+
+    FVoxelSeasonCompositionSettings Settings;
+    Settings.Corpus = &Corpus;
+    Settings.CandidateCount = 24;
+    Settings.SelectedStrateCount = 6;
+    Settings.StrateHeightInChunks = 4;
+    Settings.InterStrateGapChunks = 0;
+    Settings.OriginSpineRadius = 14.0f;
+    Settings.WorldRadiusVoxels = 0.0f;
+    Settings.OutputDirectory = FPaths::Combine(
+        FPaths::ProjectSavedDir(), TEXT("VoxelForge"), TEXT("SeasonTest"));
+    Settings.bWriteArtifacts = true;
+    Settings.bWriteReviewPage = true;
+    Settings.bIncludeCandidateAudit = true;
+
+    const int32 SeasonSeed = 0x2468;
+    const FVoxelSeasonManifest Manifest = VF_ComposeSeason(SeasonSeed, Settings);
+    TestTrue(TEXT("composition produces a usable season manifest"), Manifest.IsUsable());
+    if (!Manifest.IsUsable())
+    {
+        AddError(Manifest.Error);
+        return false;
+    }
+    TestEqual(TEXT("candidate count is the configured number of attempts"),
+              Manifest.CandidateCount, Settings.CandidateCount);
+    TestEqual(TEXT("selected count is the configured spine length"),
+              Manifest.SelectedCount, Settings.SelectedStrateCount);
+    TestEqual(TEXT("candidate audit contains every attempt"),
+              Manifest.CandidateAudit.Num(), Settings.CandidateCount);
+    TestEqual(TEXT("WorldRadiusVoxels remains zero in the artifact"),
+              Manifest.WorldRadiusVoxels, 0.0f);
+    TestEqual(TEXT("selected grounded/outlier counts add to generated slots"),
+              Manifest.GroundedSelectedCount + Manifest.OutlierSelectedCount,
+              Manifest.SelectedCount - Manifest.FixedSelectedCount);
+
+    for (int32 Index = 0; Index < Manifest.Strates.Num(); ++Index)
+    {
+        const FVoxelSeasonStrate& Strate = Manifest.Strates[Index];
+        TestEqual(FString::Printf(TEXT("slot %d keeps descent order"), Index),
+                  Strate.DepthIndex, Index);
+        TestTrue(FString::Printf(TEXT("slot %d passed non-vacuous gate"), Index),
+                 Strate.bPassedNonVacuous);
+        TestTrue(FString::Printf(TEXT("slot %d passed largest-component gate"), Index),
+                 Strate.bPassedLargestComponent);
+        TestTrue(FString::Printf(TEXT("slot %d passed primordial law"), Index),
+                 Strate.bPassedPrimordialLaw
+                     && Strate.PrimordialLawResult == EVoxelConnectivityResult::Connected);
+        TestTrue(FString::Printf(TEXT("slot %d has zero world radius"), Index),
+                 Manifest.WorldRadiusVoxels == 0.0f);
+    }
+
+    TestTrue(TEXT("season manifest JSON was emitted"), !Manifest.SerializedJson.IsEmpty());
+    TestTrue(TEXT("season manifest file was emitted"), FPaths::FileExists(Manifest.ManifestPath));
+    TestTrue(TEXT("selected-season review page was emitted"),
+             FPaths::FileExists(Manifest.ReviewPagePath));
+    FString ReviewHtml;
+    if (FFileHelper::LoadFileToString(ReviewHtml, *Manifest.ReviewPagePath))
+    {
+        TestTrue(TEXT("review page explains why each selected slot was chosen"),
+                 ReviewHtml.Contains(TEXT("Why selected:")));
+        TestTrue(TEXT("review page marks boss slots"), ReviewHtml.Contains(TEXT("Boss slot:")));
+    }
+    else
+    {
+        AddError(FString::Printf(TEXT("could not read review page %s"), *Manifest.ReviewPagePath));
+    }
+
+    // Compose again with the same inputs. SerializedJson excludes derived filesystem paths, so
+    // this is the byte-level determinism assertion for the portable artifact itself.
+    const FVoxelSeasonManifest RepeatManifest = VF_ComposeSeason(SeasonSeed, Settings);
+    TestTrue(TEXT("repeat composition is usable"), RepeatManifest.IsUsable());
+    TestEqual(TEXT("same season seed produces byte-identical JSON"),
+              RepeatManifest.SerializedJson, Manifest.SerializedJson);
+
+    FVoxelSeasonManifest LoadedManifest;
+    FString LoadReport;
+    TestTrue(TEXT("manifest loads from its JSON file"),
+             VF_LoadVoxelSeasonManifest(Manifest.ManifestPath, LoadedManifest, LoadReport));
+    if (!LoadedManifest.IsUsable())
+    {
+        AddError(LoadReport);
+        return false;
+    }
+    TestEqual(TEXT("loaded manifest has the same number of selected strates"),
+              LoadedManifest.Strates.Num(), Manifest.Strates.Num());
+
+    int64 ComparedDensitySamples = 0;
+    bool bAllDensityBitsIdentical = true;
+    for (int32 Index = 0; Index < Manifest.Strates.Num(); ++Index)
+    {
+        const FVoxelSeasonStrate& OriginalStrate = Manifest.Strates[Index];
+        const FVoxelSeasonStrate& LoadedStrate = LoadedManifest.Strates[Index];
+        TestTrue(FString::Printf(TEXT("slot %d parameter vector survives JSON bit-identically"), Index),
+                 VF_AreStrateArchetypeParamsBitIdentical(
+                     OriginalStrate.Params, LoadedStrate.Params, OriginalStrate.Archetype));
+        TestTrue(FString::Printf(TEXT("slot %d recipe survives JSON identically"), Index),
+                 VF_AreStrateStructureRecipesIdentical(
+                     OriginalStrate.Recipe, LoadedStrate.Recipe));
+
+        FVoxelOpStack OriginalStack;
+        FVoxelOpContext OriginalContext;
+        FVoxelOpStack LoadedStack;
+        FVoxelOpContext LoadedContext;
+        FString BuildError;
+        TestTrue(FString::Printf(TEXT("slot %d original stack rebuilds"), Index),
+                 VF_RebuildVoxelSeasonStrate(
+                     OriginalStrate, Manifest.OriginSpineRadius, nullptr,
+                     OriginalStack, OriginalContext, &BuildError));
+        TestTrue(FString::Printf(TEXT("slot %d loaded stack rebuilds"), Index),
+                 VF_RebuildVoxelSeasonStrate(
+                     LoadedStrate, LoadedManifest.OriginSpineRadius, nullptr,
+                     LoadedStack, LoadedContext, &BuildError));
+        if (OriginalStack.Num() == 0 || LoadedStack.Num() == 0)
+        {
+            bAllDensityBitsIdentical = false;
+            continue;
+        }
+        TestEqual(FString::Printf(TEXT("slot %d original/rebuilt stack operation count"), Index),
+                  LoadedStack.Num(), OriginalStack.Num());
+        TestEqual(FString::Printf(TEXT("slot %d original context radius"), Index),
+                  OriginalContext.WorldRadiusVoxels, 0.0f);
+        TestEqual(FString::Printf(TEXT("slot %d loaded context radius"), Index),
+                  LoadedContext.WorldRadiusVoxels, 0.0f);
+        OriginalStack.PrepareChunk(OriginalContext);
+        LoadedStack.PrepareChunk(LoadedContext);
+
+        // Compare the complete bounded probe lattice for each selected field at two-voxel
+        // spacing, not a handful of favorable points. Every sampled scalar must retain its
+        // exact IEEE-754 bits after JSON load and stack reconstruction.
+        constexpr int32 ProbeHalfExtent = 32;
+        constexpr int32 ProbeStep = 2;
+        for (int32 Z = OriginalStrate.BottomWorldZ;
+             Z < OriginalStrate.TopWorldZ && bAllDensityBitsIdentical;
+             Z += ProbeStep)
+        {
+            for (int32 Y = -ProbeHalfExtent;
+                 Y < ProbeHalfExtent && bAllDensityBitsIdentical;
+                 Y += ProbeStep)
+            {
+                for (int32 X = -ProbeHalfExtent;
+                     X < ProbeHalfExtent;
+                     X += ProbeStep)
+                {
+                    const float OriginalDensity = OriginalStack.EvalMC(
+                        static_cast<float>(X), static_cast<float>(Y), static_cast<float>(Z));
+                    const float LoadedDensity = LoadedStack.EvalMC(
+                        static_cast<float>(X), static_cast<float>(Y), static_cast<float>(Z));
+                    ++ComparedDensitySamples;
+                    if (!SameDensityBits(OriginalDensity, LoadedDensity))
+                    {
+                        bAllDensityBitsIdentical = false;
+                        AddError(FString::Printf(
+                            TEXT("slot %d density mismatch at (%d,%d,%d): 0x%08x vs 0x%08x"),
+                            Index, X, Y, Z,
+                            *reinterpret_cast<const uint32*>(&OriginalDensity),
+                            *reinterpret_cast<const uint32*>(&LoadedDensity)));
+                        break;
+                    }
+                }
+            }
+        }
+    }
+    AddInfo(FString::Printf(TEXT("round-trip density probe compared %lld bit-identical samples"),
+                            ComparedDensitySamples));
+    TestTrue(TEXT("manifest round-trip density field is bit-identical"),
+             bAllDensityBitsIdentical);
+    return true;
+}
+
+#endif

Source/VoxelForge/Private/VoxelStratePreview.cpp

@@ -979,6 +979,18 @@ bool VF_WriteStratePreviewIndex(
     SortedCandidates.Sort([](const FVoxelStratePreviewCandidate& A,
                              const FVoxelStratePreviewCandidate& B)
     {
+        if (A.bSeasonOrder != B.bSeasonOrder)
+        {
+            return A.bSeasonOrder;
+        }
+        if (A.bSeasonOrder && B.bSeasonOrder)
+        {
+            if (A.DepthIndex != B.DepthIndex)
+            {
+                return A.DepthIndex < B.DepthIndex;
+            }
+            return A.CandidateIndex < B.CandidateIndex;
+        }
         if (A.bRejected != B.bRejected)
         {
             return !A.bRejected;
@@ -1071,11 +1083,23 @@ bool VF_WriteStratePreviewIndex(
         const FString CardClass = Candidate.bRejected ? TEXT("candidate rejected") : TEXT("candidate");
         const FString MetricWindow = Candidate.Window.IsValid()
             ? Candidate.Window.Describe() : WindowDescription;
+        const int32 DisplayIndex = Candidate.bSeasonOrder && Candidate.DepthIndex != INDEX_NONE
+            ? Candidate.DepthIndex : Candidate.CandidateIndex;
         Html += FString::Printf(
             TEXT("<section class=\"%s\"><h2>#%d <span class=\"badge %s\">%s</span></h2>\n"),
-            *CardClass, Candidate.CandidateIndex, *StatusClass, *Status);
+            *CardClass, DisplayIndex, *StatusClass, *Status);
         Html += FString::Printf(TEXT("<div class=\"recipe\"><code>%s</code></div>\n"),
                                 *VF_HtmlEscape(Candidate.RecipeString));
+        if (Candidate.bSeasonOrder)
+        {
+            Html += FString::Printf(
+                TEXT("<p class=\"reason\" style=\"color:#d7e3f4\"><strong>Why selected:</strong> %s"
+                     "<br><strong>Boss slot:</strong> %s</p>\n"),
+                *VF_HtmlEscape(Candidate.SelectionReason.IsEmpty()
+                    ? TEXT("selected by the provisional season policy")
+                    : Candidate.SelectionReason),
+                Candidate.bBossSlot ? TEXT("yes") : TEXT("no"));
+        }
         if (Candidate.bRejected)
         {
             Html += FString::Printf(TEXT("<p class=\"reason\"><strong>Why rejected:</strong> %s</p>\n"),

Source/VoxelForge/Public/VoxelSeasonManifest.h

@@ -0,0 +1,269 @@
+// Offline Tier 4c season composition and the diffable Tier A manifest.
+//
+// This header deliberately describes an editor/build-box artifact. The normal runtime path still
+// receives its existing settings and builds density exactly as before; no runtime code consumes a
+// season manifest as a hidden generation fallback.
+
+#pragma once
+
+#include "CoreMinimal.h"
+#include "VoxelStrateComposer.h"
+#include "VoxelStrateMeasure.h"
+
+class UVoxelSettings;
+
+/** Why the provisional season selector put one surviving candidate in a slot. */
+enum class EVoxelSeasonSelectionReason : uint8
+{
+    Grounded,
+    Outlier,
+    Fixed,
+};
+
+/**
+ * Explicit, reviewable selection knobs for one season.
+ *
+ * None of these values is a settled definition of quality. They are the first policy Jahni can
+ * change after walking the review page. Hard validation remains separate from this policy.
+ */
+struct VOXELFORGE_API FVoxelSeasonSelectionPolicy
+{
+    // Placeholder mix only: ordinary strates give an outlier contrast. Revisit after the first
+    // season review; this is not a learned or final quality score.
+    float GroundedFraction = 0.75f;
+    float OutlierFraction = 0.25f;
+
+    // Below this measured distance two neighbours look too similar. The selector subtracts a
+    // penalty proportional to the gap; provisional because the useful contrast is visual.
+    double AdjacentSimilarityDistanceThreshold = 0.20;
+    double AdjacentSimilarityPenaltyWeight = 1.0;
+
+    // Rewards an unseen archetype/recipe in the already chosen prefix. These are variety
+    // tie-breakers, not claims that one archetype or recipe is better. Provisional review knobs.
+    double NewArchetypeBonus = 0.10;
+    double NewRecipeBonus = 0.05;
+
+    // GDD §6 says roughly every five levels, and a boss is intermediary rather than terminal.
+    // This interval is therefore an explicit provisional layout knob, not a quality score.
+    int32 BossSlotInterval = 5;
+
+    // Tier 2 hard gate: a surviving air component must retain at least this share. Provisional
+    // only in its threshold; the existence of the gate is non-negotiable for a shippable season.
+    float MinimumLargestComponentShare = 0.50f;
+
+    // Normalizers for the two unbounded measured dimensions in the adjacency distance. Fractions
+    // already live in [0,1]. These physical scales are provisional and visible in the manifest.
+    float FeatureScaleNormalizationVoxels = 256.0f;
+    float ClearanceNormalizationVoxels = 64.0f;
+};
+
+/** A caller-supplied fixed slot for tests/tools that already have a complete manifest record. */
+struct VOXELFORGE_API FVoxelSeasonFixedStrate
+{
+    int32 Seed = 0;
+    int32 HeightInChunks = 4;
+    ECaveGeneratorType Archetype = ECaveGeneratorType::TunnelNetwork;
+    FVoxelStrateArchetypeParams Params;
+    FVoxelOpStackRecipe Recipe;
+    bool bUsesRecipe = true;
+    FString SourceDefinitionPath;
+};
+
+/** Settings for the offline build-box pass. No member is consulted by normal runtime generation. */
+struct VOXELFORGE_API FVoxelSeasonCompositionSettings
+{
+    // Optional live-world settings. TotalStrates, spine/gap values, and FixedStrates are read
+    // from it when present. The pointer is borrowed for the duration of VF_ComposeSeason only.
+    const UVoxelSettings* WorldSettings = nullptr;
+
+    // Optional preloaded corpus. With nullptr the composer loads the project asset corpus on the
+    // build box, exactly like the existing offline composer tests.
+    const FVoxelStrateCorpus* Corpus = nullptr;
+
+    // 24 gives a useful minute-scale automation pass at the default coarse measurement window.
+    // Production can raise this to the overnight budget without changing the policy.
+    int32 CandidateCount = 24;
+    int32 SelectedStrateCount = 10;
+
+    // Generated candidates use one stable height. Fixed authored slots may provide their own
+    // height. World layout bounds are written into every selected parameter family below.
+    int32 StrateHeightInChunks = 4;
+    int32 InterStrateGapChunks = 0;
+    float OriginSpineRadius = 14.0f;
+    float WorldRadiusVoxels = 0.0f;
+
+    // Coarse measurement is deliberately bounded. Tests may reduce the window; production may
+    // spend the overnight budget on a finer pass after the selector has been judged.
+    FVoxelStrateMeasureSettings MeasureSettings;
+    FVoxelSeasonSelectionPolicy SelectionPolicy;
+
+    // Explicit composed fixed slots take precedence. When empty, the composer adapts the
+    // existing UVoxelSettings::FixedStrates map, preserving its absolute slot indices.
+    TMap<int32, FVoxelSeasonFixedStrate> FixedStrates;
+
+    // Empty means ProjectSavedDir()/VoxelForge/Seasons. Files are never written to the runtime
+    // content directory by this API.
+    FString OutputDirectory;
+    bool bWriteArtifacts = true;
+    bool bWriteReviewPage = true;
+    bool bIncludeCandidateAudit = true;
+
+    // Informational only; when WorldSettings is present CurrentSeason supplies the default.
+    int32 SeasonNumber = 0;
+
+    FVoxelSeasonCompositionSettings()
+    {
+        // The existing Tier 4b test uses step 4. Season composition defaults to step 8 so the
+        // default automation artifact is measured in minutes, while MaxCells remains bounded.
+        MeasureSettings.SampleStep = 8;
+        MeasureSettings.RadiusInVoxels = 256;
+        MeasureSettings.MaxCells = 8000000;
+        MeasureSettings.MaxRouteRetries = 16;
+        MeasureSettings.HeadroomCells = 2;
+        MeasureSettings.InteriorMarginVoxels = -1;
+    }
+};
+
+// Friendly aliases for callers that use the task's shorter naming.
+using FVoxelSeasonComposerSettings = FVoxelSeasonCompositionSettings;
+using FVoxelSeasonComposeSettings = FVoxelSeasonCompositionSettings;
+
+/** Compact audit row; the full vectors live only for selected strates. */
+struct VOXELFORGE_API FVoxelSeasonCandidateAudit
+{
+    int32 CandidateIndex = INDEX_NONE;
+    int32 Seed = 0;
+    ECaveGeneratorType Archetype = ECaveGeneratorType::TunnelNetwork;
+    uint32 RecipeHash = 0;
+    double DistanceFromCorpusCentroid = 0.0;
+    bool bPassedHardGates = false;
+    bool bSelected = false;
+    FString RejectionReason;
+};
+
+/** Count of one explicit hard-gate or final-placement rejection reason. */
+struct VOXELFORGE_API FVoxelSeasonRejectionCount
+{
+    FString Reason;
+    int32 Count = 0;
+};
+
+/** One ordered Tier A spine entry. */
+struct VOXELFORGE_API FVoxelSeasonStrate
+{
+    // DepthIndex is the absolute world-layout slot. CandidateIndex is the offline attempt id.
+    int32 DepthIndex = INDEX_NONE;
+    int32 CandidateIndex = INDEX_NONE;
+    int32 Seed = 0;
+    int32 HeightInChunks = 0;
+    int32 TopWorldZ = 0;
+    int32 BottomWorldZ = 0;
+
+    ECaveGeneratorType Archetype = ECaveGeneratorType::TunnelNetwork;
+    FVoxelOpStackRecipe Recipe;
+    FVoxelStrateArchetypeParams Params;
+    FVoxelStrateMeasuredMetrics Metrics;
+
+    double DistanceFromCorpusCentroid = 0.0;
+    FString SelectionReason;
+    FString SourceDefinitionPath;
+
+    bool bGrounded = false;
+    bool bOutlier = false;
+    bool bBossSlot = false;
+    bool bFixed = false;
+    bool bUsesRecipe = true;
+
+    bool bPassedNonVacuous = false;
+    bool bPassedLargestComponent = false;
+    bool bPassedPrimordialLaw = false;
+    EVoxelConnectivityResult PrimordialLawResult = EVoxelConnectivityResult::OutOfWindow;
+};
+
+/**
+ * The stored Tier A season artifact.
+ *
+ * Tier B is intentionally absent: its hash-lattice field remains an arithmetic/enumeration API,
+ * not a second stored table. Strates is ordered from the surface down and is the only finite spine
+ * persisted by this task.
+ */
+struct VOXELFORGE_API FVoxelSeasonManifest
+{
+    static constexpr int32 CurrentSchemaVersion = 1;
+
+    bool bValid = false;
+    int32 SchemaVersion = CurrentSchemaVersion;
+    FString Error;
+
+    int32 Season = 0;
+    int32 Seed = 0;
+    uint32 InputCorpusHash = 0;
+    int32 CandidateCount = 0;
+    int32 SurvivorCount = 0;
+    int32 SelectedCount = 0;
+    int32 RejectedCount = 0;
+    int32 GroundedSelectedCount = 0;
+    int32 OutlierSelectedCount = 0;
+    int32 FixedSelectedCount = 0;
+    int32 TotalStrates = 0;
+    int32 InterStrateGapChunks = 0;
+    float OriginSpineRadius = 0.0f;
+    float WorldRadiusVoxels = 0.0f;
+
+    FVoxelSeasonSelectionPolicy SelectionPolicy;
+    FString PolicyNote;
+
+    TArray<FVoxelSeasonStrate> Strates;
+    TArray<FVoxelSeasonCandidateAudit> CandidateAudit;
+    TArray<FVoxelSeasonRejectionCount> RejectionCounts;
+
+    // Derived artifact locations; intentionally not serialized into the portable JSON.
+    FString ManifestPath;
+    FString ReviewPagePath;
+    FString SerializedJson;
+
+    bool IsUsable() const
+    {
+        return bValid && Error.IsEmpty() && WorldRadiusVoxels == 0.0f
+            && Strates.Num() == SelectedCount && SelectedCount > 0;
+    }
+};
+
+/** Human-readable enum names used by JSON and the review page. */
+VOXELFORGE_API const TCHAR* VF_GetVoxelSeasonSelectionReasonName(
+    EVoxelSeasonSelectionReason Reason);
+
+/** Compose, validate, select, serialize, and (by default) write one season. Editor/build-box only. */
+VOXELFORGE_API FVoxelSeasonManifest VF_ComposeSeason(
+    int32 SeasonSeed, const FVoxelSeasonCompositionSettings& Settings);
+
+/** Convenience overload that adapts the existing runtime settings asset. */
+VOXELFORGE_API FVoxelSeasonManifest VF_ComposeSeason(
+    int32 SeasonSeed, const UVoxelSettings* WorldSettings);
+
+/** Serialize/read the complete Tier A manifest as stable pretty JSON. */
+VOXELFORGE_API FString VF_SerializeVoxelSeasonManifest(
+    const FVoxelSeasonManifest& Manifest);
+VOXELFORGE_API bool VF_SaveVoxelSeasonManifest(
+    const FString& ManifestPath, const FVoxelSeasonManifest& Manifest, FString& OutReport);
+VOXELFORGE_API bool VF_LoadVoxelSeasonManifest(
+    const FString& ManifestPath, FVoxelSeasonManifest& OutManifest, FString& OutReport);
+
+/** Rebuild exactly the stack represented by one manifest entry. */
+VOXELFORGE_API bool VF_BuildSeasonStrateStack(
+    const FVoxelSeasonStrate& Strate,
+    float SpineRadius,
+    const UVoxelStrateManager* StrateManager,
+    FVoxelOpStack& OutStack,
+    FVoxelOpContext& OutContext,
+    FString* OutError = nullptr);
+
+/** Verbose alias for tests/tools that want the round-trip operation named explicitly. */
+VOXELFORGE_API bool VF_RebuildVoxelSeasonStrate(
+    const FVoxelSeasonStrate& Strate,
+    float SpineRadius,
+    const UVoxelStrateManager* StrateManager,
+    FVoxelOpStack& OutStack,
+    FVoxelOpContext& OutContext,
+    FString* OutError = nullptr);
+

Source/VoxelForge/Public/VoxelStrateComposer.h

@@ -18,6 +18,16 @@ class UVoxelSettings;
 class UVoxelStrateDefinition;
 class UVoxelStrateManager;
 
+#if WITH_EDITOR
+// The complete definitions live in VoxelSeasonManifest.h. Keeping this forward declaration here
+// makes the Tier 4c entry point discoverable from the composer header without creating a circular
+// include (the manifest header includes this one for the existing vector/recipe types).
+struct FVoxelSeasonManifest;
+struct FVoxelSeasonCompositionSettings;
+VOXELFORGE_API FVoxelSeasonManifest VF_ComposeSeason(
+    int32 SeasonSeed, const FVoxelSeasonCompositionSettings& Settings);
+#endif
+
 /** The one-bit identity choice at the root of a rolled structure. */
 UENUM(BlueprintType)
 enum class EVoxelStrateRootPolarity : uint8

Source/VoxelForge/Public/VoxelStratePreview.h

@@ -71,6 +71,12 @@ struct VOXELFORGE_API FVoxelStrateFinePreviewSettings
 struct VOXELFORGE_API FVoxelStratePreviewCandidate
 {
     int32 CandidateIndex = INDEX_NONE;
+    // Season pages deliberately opt into descent order. The ordinary candidate contact sheet
+    // keeps its survivor/outlier ordering; a season review must read top-to-bottom like play.
+    bool bSeasonOrder = false;
+    int32 DepthIndex = INDEX_NONE;
+    FString SelectionReason;
+    bool bBossSlot = false;
     FVoxelStratePreviewWindow Window;
     FString RecipeString;
     FString ArrivalDepartureVerdict;