wip(assembler): M2 round 2 -- same-LOD borders watertight for MC/hybrid/DC; LOD0/1 transitions still open

Shared halo + deterministic border-quad ownership + T-junction conformance: 625/625 same-LOD for all three.
LOD 2:1 prototype (collar zipper) fails MC 5 / hybrid 38 / DC 40 cases (corners, overhangs).
Hybrid is bit-identical to MC on a sampled native SurfaceWorld cliff; DC rougher. Standalone only.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MmSoF64BbRFmk9C3p1VsBJ

Standalone/Research/WorldAssemblerM2/REPORT.md

@@ -1,125 +1,126 @@
-# World assembler M2 round 1: sharp-mesher decision spike
+# World assembler M2 round 2 — standalone border closure
 
 Date: 2026-10-10  
-Status: **Gate failed; no production mesher selected.** Hybrid is the leading candidate for an in-game follow-up, but it does not pass independent tile seams. Every candidate fails the tested LOD0/LOD1 seam.
+Status: **same-LOD gate passed; full LOD0/LOD1 gate failed; no production mesher selected.**
 
 ## Decision
 
-At 25 cm, feature-aware DC substantially reduces sharp-feature field residual and preserves hard normal splits. The hybrid also leaves the smooth cave-chamber wall on the MC path, where its measured residual matches MC. Its 8-worker mesh cost is about 4.4% above MC.
+The hybrid now closes the same-LOD tile-border suite: 625/625 cases, with zero unmatched contour probes, open edges, or nonmanifold edges. MC retains its 625/625 pass, and DC also passes as a reference after the same assembly repair.
 
-Those gains are not enough to choose it: hybrid fails all 500 tagged-shape independent tile-border cases, and DC everywhere fails all 625. MC passes all 625 same-LOD tile-border cases but retains large sharp-feature bevel residual and also fails every LOD transition case. No candidate passes both border gates. Hold architectural recipes until a real border/transition implementation passes.
+The 2:1 LOD transition is still not ready. The sharp cliff crossing fixture passes for MC, hybrid, and DC, but the complete 625-case suite has failures on corners, overhangs, a doorway, and two DC cave cases. The contact sheet makes the sharp-feature improvement visible, but the failed full transition gate blocks a production choice and an Unreal implementation this round.
 
-Round 2 should take MC and hybrid into Unreal as opt-in, versioned recipe candidates. Hybrid is the primary quality candidate; MC is the baseline and organic fallback. Bring neighbor halo/ownership rules, a 2:1 transition template or equivalent, and actual collision cooking. Compare the five fixtures in-game with matched cameras, including same-LOD and LOD0/LOD1 borders. Keep DC-everywhere as a reference unless its organic quality and border results improve.
+Keep MC as the baseline and hybrid as the sharp-feature candidate. Keep DC-everywhere as a reference; it remains rougher on the sampled native patch. Continue standalone work on a topology-aware 2:1 transition before taking a candidate into Unreal.
 
-## Test setup
+## Harness and gates
 
-The standalone C++20 harness uses the plugin’s canonical marching-cubes lookup table and 25 cm cells. It builds a 32³-cell, 8 m tile for each fixture. The lattice phase sweep translates each analytic field by 0, 5, 10, 15, and 20 cm on each axis: 125 phases per fixture and method, 1,875 phase meshes total.
+The standalone C++20 spike uses 25 cm cells and five fixtures: a 90-degree corner, doorway, one-metre riser, cliff ledge/overhang, and analytic cave chamber. Each fixture is translated through 125 lattice phases (0, 5, 10, 15, and 20 cm per axis). The retained outputs are [phase_sweep.csv](results/phase_sweep.csv), [cost.csv](results/cost.csv), [determinism.csv](results/determinism.csv), and [seams.csv](results/seams.csv).
 
-The fixtures are a union-of-boxes 90° corner, a box doorway with an analytic void, a one-metre riser, a cliff ledge/overhang, and a smooth spherical cave-chamber cavity. The chamber has negative density in solid rock and positive density in its air cavity, following the plugin sign convention. It is an analytic curved proxy, not a sampled native cave or SurfaceWorld patch.
+Same-LOD neighbors are sampled independently with a shared field halo and deterministic ownership of border quads. The assembled pair is checked after open-edge T-junction subdivision; the subdivision preserves the source triangle footprint. Hybrid/DC independent contours are also compared from temporary witness meshes. No shared surface mesh is clipped and reused for the neighbor comparison.
 
-The candidates are:
+LOD0/LOD1 uses independent 25 cm and 50 cm half-grids at a 2:1 ratio. The spike clips their surfaces at the border and tries a collar/chain zipper; a residual closed seam loop is capped only when its own sampled field residual is within budget. This is a tested transition prototype, not a complete Transvoxel table.
 
-- **MC:** table-driven marching cubes with linear edge roots and interpolated central-difference field normals. This preserves MC geometry while giving it a fair smooth-normal path.
-- **Hybrid:** untagged connected surface components use MC. Components connected to analytic sharp-plane feature tags use dual contouring.
-- **DC:** dual contouring on every surface component, including the cave-chamber wall.
+The physical error budget is **0.50 m**, one LOD1 sample interval. This is a conservative, camera-independent limit that is easy to audit in the field. It does not establish a screen-space guarantee; round 3 must also check projected error at the target cameras.
 
-DC uses Hermite roots, a fixed-order 3×3 QEF solve, a small center penalty for rank-deficient constraints, cell-bound clamping, deterministic feature selection, and position quantization at 1/65,536 voxel. All candidates share a 0.01 mm positive bias for exact-zero lattice samples. No LOD transition template is implemented in this spike; independent fine/coarse half meshes are compared directly to expose that gate.
+## Same-LOD border results
 
-Phase and same-resolution seam sweeps use the five phase offsets above. Same-LOD borders compare independently generated 8 m tiles on either side of x=0. LOD borders compare an independently generated 25 cm half tile against an independently generated 50 cm half tile. Border contours are compared in both directions at five points per segment. A missing contour is recorded as unmatched; the topological audit counts geometric boundary and nonmanifold edges after merging the independent meshes.
+Each method has 625 independently generated neighbor cases. “Bad” includes unmatched probes, boundary edges, and nonmanifold edges after assembly.
 
-## Surface residual and crease normals
+| Method | Bad cases | Unmatched probes | Open edges | Nonmanifold edges | Maximum contour mismatch |
+|---|---:|---:|---:|---:|---:|
+| MC | 0 / 625 | 0 | 0 | 0 | 0 m |
+| Hybrid | 0 / 625 | 0 | 0 | 0 | 0 m |
+| DC | 0 / 625 | 0 | 0 | 0 | 0 m |
 
-The residual is the absolute analytic field value, in metres, sampled at each triangle’s three vertices, three edge midpoints, and centroid. The table shows the equal-weight mean of the 125 phase means and the maximum sample over all phases. Repeated vertex samples count repeatedly. This is a useful analytic-field residual, not a symmetric Hausdorff distance.
+The merge-time T-junction conformance added 52 triangles across Hybrid’s suite and 40 across DC’s; MC needed none. Its measured added-triangle field residual is 0 m at the CSV precision. The full per-case data is in [seams.csv](results/seams.csv).
 
-| Fixture | MC mean / max (cm) | Hybrid mean / max (cm) | DC mean / max (cm) |
-|---|---:|---:|---:|
-| 90° corner | 0.51 / 16.67 | 0.17 / 6.25 | 0.17 / 6.25 |
-| Doorway | 0.99 / 16.67 | 0.41 / 12.50 | 0.41 / 12.50 |
-| One-metre riser | 0.46 / 16.67 | 0.15 / 6.25 | 0.15 / 6.25 |
-| Cliff ledge / overhang | 0.49 / 16.67 | 0.16 / 6.25 | 0.16 / 6.25 |
-| Cave-chamber wall | 0.39 / 1.17 | 0.39 / 1.17 | 0.50 / 4.75 |
+## 2:1 LOD transition results
 
-MC’s worst sharp residual is 16.67 cm at this phase sample, close to the expected 17.68 cm half-diagonal bevel bound. Hybrid/DC reduce the sharp residual while DC-everywhere is rougher on the smooth chamber than either MC path.
+The full gate still fails. Raw fine/coarse contour comparisons stay below the 0.50 m budget, but the transition surface/topology does not close all cases.
 
-Crease split rate counts adjacent triangles with distinct analytic feature labels and face-normal angle above 30°. A split is counted when their average interpolated/vertex normals also differ by more than 30°.
+| Method | Bad cases | Seam-band open edges | Seam-band nonmanifold edges | Worst raw contour mismatch | Worst transition field residual |
+|---|---:|---:|---:|---:|---:|
+| MC | 5 / 625 | 15 | 5 | 0.318199 m | 0.250008 m |
+| Hybrid | 38 / 625 | 4,213 | 47 | 0.158352 m | 1.24975 m |
+| DC | 40 / 625 | 4,465 | 49 | 0.158352 m | 1.96263 m |
 
-| Fixture | MC split rate | Hybrid split rate | DC split rate |
-|---|---:|---:|---:|
-| 90° corner | 11.83% | 99.93% | 99.93% |
-| Doorway | 24.31% | 100.00% | 100.00% |
-| One-metre riser | 12.98% | 99.99% | 99.99% |
-| Cliff ledge / overhang | 15.18% | 99.89% | 99.89% |
-| Cave-chamber wall | no tagged crease | no tagged crease | no tagged crease |
+Failures by fixture: MC has five doorway cases; Hybrid has 25 corner and 13 overhang cases; DC has those same 38 plus two organic-cave cases. Hybrid/DC transition residuals exceed the 0.50 m budget on the corner cases. Some remaining rows have open or nonmanifold seam edges even when the raw contour mismatch is small. The full CSV keeps pre-transition and internal topology counts separate. The unrestricted-cap diagnostic is preserved in [seams_cap_unbounded_diagnostic.csv](results/seams_cap_unbounded_diagnostic.csv).
 
-## Topology and independent borders
+The dedicated sharp cliff crossing case passes all three methods: zero unmatched probes, open edges, and nonmanifold edges. Its maximum raw contour mismatch is 0.249977 m for MC and 0.419411 m for Hybrid/DC; the transition field residual maxima are 0.233333 m and 0.238888 m respectively. See [lod_cliff_crossing.csv](results/lod_cliff_crossing.csv).
 
-The phase meshes themselves have no nonmanifold edges. MC has 0 open-edge meshes in 625 fixture/phase cases. Hybrid and DC each have 36 open-edge meshes in 625, summing to 116 open edges across those cases.
+The remaining Unreal-only checks are actual `UBodySetup` collision cooking/contact, projected pixel error at the game cameras, and runtime task scheduling/upload against the plugin mesher. None of those can repair the standalone topology failures; the topology gate is still the reason to defer Unreal integration.
 
-Independent-border results aggregate 625 fixture/phase cases per method. “Bad” means unmatched seam probes, boundary edges, or nonmanifold edges. No nonmanifold edges were found.
+### Production skirt baseline
 
-| Method | Same-LOD bad cases / 625 | Same-LOD open edges | Same-LOD unmatched probes | LOD0/LOD1 bad cases / 625 | LOD0/LOD1 open edges | LOD0/LOD1 unmatched probes |
+The current plugin skirt depth is `max(1, SkirtCells) × Step × GeometryVoxelSize`; skirts are normal-extruded, double-sided visual strips. With Core’s 25 cm geometry voxel size and the default `SkirtCells = 4`, nominal depth is 1 m at LOD0 and 2 m at LOD1. Project settings can override these defaults. Skirts hide many visual gaps but do not make the neighboring surface topologically watertight. The new transition has not yet replaced that production behavior.
+
+## Surface residual and crease splits
+
+Residual is the absolute field value sampled at triangle vertices, edge midpoints, and centroids; it is not a symmetric Hausdorff distance. Values below average the 625 phase rows per method; maxima are the worst sampled value.
+
+| Method | Mean residual | Worst residual | Tagged crease pairs | Normal split pairs | Split rate on tagged creases | Mean triangles / vertices |
 |---|---:|---:|---:|---:|---:|---:|
-| MC | 0 | 0 | 0 | 625 | 75,494 | 0 |
-| Hybrid | 500 | 85,632 | 3,484 | 625 | 75,794 | 5,819 |
-| DC | 625 | 101,440 | 3,609 | 625 | 75,790 | 6,128 |
+| MC | 0.5664 cm | 16.6670 cm | 10,926 | 1,847 | 16.90% | 3,363.1 / 1,728.8 |
+| Hybrid | 0.2552 cm | 12.5027 cm | 140,876 | 140,806 | 99.95% | 3,365.3 / 3,469.2 |
+| DC | 0.2786 cm | 12.5027 cm | 140,876 | 140,806 | 99.95% | 3,365.8 / 1,985.6 |
 
-MC’s same-LOD contour match is exact in all cases: zero measured contour distance and zero merged open edges. Hybrid passes only the 125 smooth chamber cases; its 500 tagged-shape cases have open edges. DC also fails the chamber border.
+The hybrid keeps untagged/organic components on MC and uses DC for tagged sharp features. It preserves the sharp corner/riser/ledge better than MC in the analytic fixtures, while its feature splits roughly double the vertex count.
 
-Every LOD0/LOD1 case has open boundary edges. For MC, the per-case maximum sampled contour distance has an 18.57 cm median, 26.41 cm 95th percentile, and 31.82 cm worst case; 39 of 625 cases exceed 25 cm. Hybrid has complete contour comparisons in only 130 cases; five of those exceed 25 cm, with a 560.47 cm worst finite comparison. DC has complete contour comparisons in only five cases, with a 560.47 cm worst finite comparison. The large finite outliers and unmatched probes are direct failures, not a pass hidden by averages. The spike has no transition templates, so these results are a transition gate, not a claim that any candidate’s final transition design has been tuned.
+## Sampled native SurfaceWorld cliff
 
-## Cost, determinism, and collision proxy
+The native comparison samples the 8 m patch at 25 cm from the M1 SurfaceWorld manifest (feature type 4, feature `0x9812c26310b90c9`, manifest hash `0x8933693d9560ba9f`). MC and Hybrid emit bit-identical vertex and triangle arrays, with identical mesh hash `0x9d58e0603f1bf9c7`: 2,345 vertices and 4,496 triangles each. This confirms that the hybrid leaves this untagged native patch unchanged.
 
-Each timing uses an already sampled 32³-cell field grid, three mesh builds, and the median build time. Field sampling, Unreal scheduling, upload, collision cooking, and rendering are excluded. All values below average the five fixtures.
+The sampled scalar-field residual is 0.212167 m mean and 16.0068 m max for both MC and Hybrid. This patch is cropped at the 8 m volume boundary and has 192 boundary edges; these values are not a seam result, and the scalar field is not a signed-distance guarantee. DC-everywhere differs (2,247 vertices, 3,961 triangles, 4.57272 m mean / 16.5898 m max, 504 boundary edges and 74 nonmanifold edges). The native CSV is [native_surface.csv](results/native_surface.csv).
 
-| Worker count | MC mean ms/tile | Hybrid mean ms/tile | DC mean ms/tile |
+## Cost and determinism
+
+The timer starts after the 32³ field grid is sampled, measures meshing only, and excludes Unreal scheduling, upload, collision cooking, and rendering. Values below are the median of five fixture medians; W1/W8 use three builds, while W16 uses one timed build because repeated W16 thread creation had caused a host access violation. Hash determinism is still checked at all three worker counts.
+
+| Workers | MC ms/tile | Hybrid ms/tile | DC ms/tile |
 |---:|---:|---:|---:|
-| 1 | 16.308 | 17.375 | 16.269 |
-| 8 | 14.275 | 14.907 | 13.996 |
-| 16 | 14.555 | 15.291 | 14.129 |
+| 1 | 16.316 | 17.534 | 16.417 |
+| 8 | 53.914 | 54.840 | 52.606 |
+| 16 | 86.961 | 90.490 | 89.476 |
 
-At W8, hybrid is 4.4% slower and DC is 2.0% faster than MC. Mean triangle counts are 3,454.4 / 3,456.8 / 3,457.6 for MC / Hybrid / DC. Mean vertex counts are 1,728.8 / 3,469.2 / 1,985.6. Hybrid’s feature-split path therefore roughly doubles output vertices for negligible triangle change.
+All 45 W1/W8/W16 rows match the W1 hash for that method and fixture. The standalone collision proxy copies the render mesh: all hashes match and measured geometry delta is 0 m. This does not test Unreal collision cooking.
 
-All 45 determinism rows (five fixtures × three methods × three worker counts) match the W1 reference for that fixture and method: zero cross-worker hash mismatches. W16 is a 16-worker software pool running with process affinity limited to eight logical CPUs.
+These timings are **not comparable to the optimized production MC mesher**. The harness is a separate STL/map-based implementation with its own worker dispatch and already-sampled grid; the strong slowdown at W8/W16 is further evidence not to use these numbers as a production estimate. They are useful only for comparisons within this harness.
 
-The standalone collision proxy is the same emitted vertex/triangle mesh. All 45 proxy hashes match the visual mesh hash and report 0 m geometry delta. This verifies the candidate mesh handoff only; there is no independent collision simplification, Unreal physics cook, or contact test in round 1.
+## Contact sheet
 
-## Captures
+The [updated offline contact sheet](results/captures/contact_sheet.jpg) is 864 × 1,968 pixels. It contains the five analytic fixtures, the sampled SurfaceWorld cliff, and both LOD seam views, with MC/Hybrid/DC columns. The 24 individual JPEGs are 288 × 246 pixels; all 25 files including the sheet are below 300 KB. No viewer or GPU path was used.
 
-The [contact sheet](results/captures/contact_sheet.jpg) is an offline orthographic rasterization of matched MC, Hybrid, and DC meshes for all five fixtures, plus one LOD seam view per method. It is 864 × 1,476 pixels. The 18 individual captures are 288 × 246 pixels. There are 19 JPEGs including the sheet; all are under 300 KB, and the largest is the 128,260-byte contact sheet. No viewer was launched.
+## Recommendation and round-3 Unreal plan
 
-Capture files:
+Do not select or enable the hybrid in the owner project yet. The same-LOD gate is closed, but the full LOD gate is not. The current Core world hash/default path is untouched.
 
-- [90° corner — MC](results/captures/corner90_MC.jpg), [Hybrid](results/captures/corner90_Hybrid.jpg), [DC](results/captures/corner90_DC.jpg)
-- [Doorway — MC](results/captures/doorway_MC.jpg), [Hybrid](results/captures/doorway_Hybrid.jpg), [DC](results/captures/doorway_DC.jpg)
-- [One-metre riser — MC](results/captures/riser1m_MC.jpg), [Hybrid](results/captures/riser1m_Hybrid.jpg), [DC](results/captures/riser1m_DC.jpg)
-- [Cliff ledge — MC](results/captures/cliff_overhang_MC.jpg), [Hybrid](results/captures/cliff_overhang_Hybrid.jpg), [DC](results/captures/cliff_overhang_DC.jpg)
-- [Cave chamber — MC](results/captures/organic_cave_chamber_MC.jpg), [Hybrid](results/captures/organic_cave_chamber_Hybrid.jpg), [DC](results/captures/organic_cave_chamber_DC.jpg)
-- [LOD seam — MC](results/captures/lodseam_MC.jpg), [Hybrid](results/captures/lodseam_Hybrid.jpg), [DC](results/captures/lodseam_DC.jpg)
+When the standalone LOD gate passes, round 3 should:
 
-## Run ledger and constraints
+1. Add an **opt-in, versioned** recipe such as `WorldAssemblerHybridV1`, default off, with its mesher, feature ownership, transition, and collision settings recorded as part of the version. Keep the existing Core recipe and default hashes unchanged.
+2. Add an Unreal test map with the five analytic fixtures, the sampled SurfaceWorld cliff, and a native Core cave tile. Include independent same-LOD neighbors and a sharp cliff crossing from LOD0 to LOD1. Compare skirts on/off and use matched cameras plus wireframe views.
+3. Cook collision through the real Unreal path. Wait for cooking completion, then run capsule sweeps/walk tests over the doorway, riser, cliff underside, cave wall, and both borders. Check collision/render agreement and recooking after a local edit.
+4. Record mesh and collision cook latency, CPU/memory, triangle/vertex counts, LOD error in pixels at the fixture cameras, and player contact results. Keep MC as the direct baseline and preserve a one-switch rollback to the existing recipe.
+
+## Run ledger and scope
 
 | Run/check | Result |
 |---|---|
-| Final MSVC C++20 build | Passed in 4.42 s, BelowNormal, affinity 0xFF00. |
-| Final phase/cost/determinism/seam run | Passed in 114.208 s; 1,875 phase meshes and 1,875 independent seam cases, BelowNormal, affinity 0xFF00. |
-| Final capture renderer | Passed in 2.61 s, BelowNormal, affinity 0xFF00; 19 files under the 300 KB cap. |
-| Earlier phase run 1 | Exited normally in 31.14 s; exact-zero lattice degeneracies exposed topology defects. |
-| Earlier phase run 2 | Exited normally in 31.11 s after adding the deterministic exact-zero bias; DC still had boundary defects. |
-| Earlier phase run 3 | Exited normally in 35.07 s after splitting disconnected cell patches; remaining boundary defects kept it from acceptance. |
-| Earlier phase run 4 | Exited normally in 36.55 s after making MC endpoint-gradient interpolation explicit; used for normal-split comparison. |
-| Earlier seam run | Exited normally in 74.21 s, but clipped a shared mesh and did not test independently generated borders. It was superseded by the final independent-neighbor seam run. |
-| Tool validation | One early PowerShell parser check used an invalid reference argument. Two later analysis-only PowerShell aggregation commands had syntax errors. All were corrected; none launched a mesher process. One early MSVC environment setup printed a nonfatal vswhere helper warning; compilation succeeded, and the final build emitted no warning. |
+| Final MSVC C++20 build | Passed in 5.44 s, BelowNormal, affinity `0xFF00`. |
+| Full seam run with unrestricted residual-loop caps | Completed in 602.78 s; 83 LOD cases failed. Preserved as `results/seams_cap_unbounded_diagnostic.csv`. |
+| Final full seam run with 0.50 m cap-residual guard | Completed in 601.31 s; same-LOD passed 625/625 for all methods, LOD failures were MC 5, Hybrid 38, DC 40. No crash or guard trip. |
+| Cost/phase/native analysis | Completed in 120.95 s; 1,875 phase rows, 45 determinism rows, native patch comparison. |
+| Final offline renderer | Passed in 3.14 s; 25 JPEGs under the 300 KB cap. |
+| Earlier full seam variants | Completed in 559.32 s and 566.44 s. Both failed earlier same-LOD Hybrid/DC cases (36/625 each); superseded by the final T-junction conformance pass. |
+| Focused transition prototypes | Completed within seconds. Earlier MC doorway variants left 64, then 3–4 open edges; whole-mesh endpoint snapping introduced nonmanifold edges. Those variants were rejected. The bounded residual-loop cap closes this focused doorway case, but the full LOD matrix still fails. |
+| Earlier native halo diagnostic | An initial process exited `0xC0000005`; an AddressSanitizer launch first failed `0xC0000135` because its runtime DLL was unavailable. After using the Visual Studio runtime path, ASan found the halo index overflow; the indexing was fixed, and subsequent harness runs completed. |
+| W16 timing diagnostic | Repeated creation/timing of 16 OS workers caused a host access violation. W16 now uses one timed build; hash determinism remains checked. |
+| Aggregation tools | Two PowerShell summary attempts had query errors, including a missing `vertices` field in `phase_sweep.csv`; corrected queries ran without launching a mesher. No `0xC0000142` retry was needed. |
 
-Every final build/test/render process used BelowNormal priority and affinity 0xFF00, limiting it to eight of the 16 logical processors. The build/test/render scripts enforce an 8 GB private-memory guard and 15-minute timeout. No process hit either limit, crashed, or needed a 0xC0000142 retry. The earlier phase runs above exited normally; their topology/seam measurements failed or were superseded as noted. No viewer or owner editor was opened. No owner project was built and no .uasset was touched.
+Every final build, mesher, analysis, and renderer process ran BelowNormal with affinity `0xFF00`; the scripts enforce an 8 GB private-memory limit and 15-minute timeout. Peak observed mesher private memory was under 0.2 GB. No final process crashed, exceeded a limit, or needed a retry.
 
-## Files added for the spike
+All edits and outputs are under `Plugins/VoxelForge/Standalone/Research/WorldAssemblerM2`, plus this dialogue log. No `Source/` file, Core source, owner project file, `.uasset`, or editor was touched. No commit, push, or stash was made.
 
-New implementation and launch files:
+## Files changed and new source files
 
-- [SharpMesherSpike.cpp](SharpMesherSpike.cpp)
-- [BuildSharpMesherSpike.ps1](BuildSharpMesherSpike.ps1)
-- [RunSharpMesherSpike.ps1](RunSharpMesherSpike.ps1)
-- [RenderSharpMesherCaptures.ps1](RenderSharpMesherCaptures.ps1)
-- [RenderSharpMesherCaptures.py](RenderSharpMesherCaptures.py)
+Updated existing standalone files: [SharpMesherSpike.cpp](SharpMesherSpike.cpp), [BuildSharpMesherSpike.ps1](BuildSharpMesherSpike.ps1), [RunSharpMesherSpike.ps1](RunSharpMesherSpike.ps1), and [RenderSharpMesherCaptures.py](RenderSharpMesherCaptures.py). Updated this report and appended the M2 round-2 dialogue entry.
 
-The report, CSV measurements, exported OBJ meshes, offline captures, executable/object build outputs, and run logs are also in this WorldAssemblerM2 directory. No files under Source were changed.
+**New source files this round: none.** CSVs, OBJ meshes, JPEG captures, logs, and local build outputs are generated research artifacts; none were committed.