wip(assembler): M1 round 4 PARTIAL -- stopped at owner's request (GPU coil whine at night)

Unverified mid-round state (cliff plates / horizon slab / routes in progress). Resume from here.

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

ARCHITECTURE.md

@@ -1165,7 +1165,7 @@ choices for the next implementation pass:
 | TunnelNetwork | Keep the native primitive representation; add missing density operators as measured. | Existing rooms, tunnels, and passage chains work, but the 16-tile probe still changed 2.17% of signs and had a 1.01 m mean sampled surface distance. |
 | FlatPlain and CrystalChamber | Native slab operator using the already copied slab parameters. | Floor, ceiling, columns, and crystal ceiling are a distinct low-cost structure; generic cave primitives do not express them. |
 | Maze | Native deterministic cell graph and corridor field using FMazeGenerationParams. | The legacy topology is seed-stable and compact; current generic caves changed 13.34% of signs and had a 5.92 m maximum sampled surface distance. |
-| SurfaceWorld | Native Core heightfield long term; retain the exact legacy density bridge temporarily. | The bridge gives exact tested density hashes but runs near owner-field cost and does not add render-side water or biome materials. |
+| SurfaceWorld | Keep the exact bridge as the Unreal runtime path until the standalone native evaluator is integrated and owner-reviewed. | The native fixed-scale heightfield, route plan and field sweep now exist in `Standalone/Core`; the plugin season/hash path and in-game review remain open. The bridge still lacks render-side water and biome materials. |
 | VerticalShafts | Native deterministic shaft/ledge field; use legacy fallback only as a short compatibility step. | Generic cave shapes produced no matching surface in the probe and failed the passage-centerline audit. |
 | FloatingIslands | Native island SDF with deterministic placement and smooth unions. | The current probe changed 95.75% of signs; an island layout is sparse and does not map well to room/tunnel primitives. |
 | Underwater | Reuse native TunnelNetwork geometry and add an explicit water render payload. | The density field can reuse cave geometry; water material/plane is separate from signed density and remains absent. |
@@ -1178,6 +1178,14 @@ worker path explicit and avoids charging every sample for a second field impleme
 continues to verify the opt-in Unreal route and its 25 cm Core scale; it does not certify the missing
 archetypes.
 
+**Standalone SurfaceWorld M1 progress (2026-10-09):** `WorldAssemblyManifest` evaluator 4 now
+serializes a finite-strate surface route with stable waypoint IDs, a 0.34 m × 1.76 m player capsule,
+a 15° grade limit and underfoot support constraints. The final composed field must pass a capsule
+sweep before a route candidate is accepted. Cliff shelves carry a two-Core-voxel minimum thickness.
+The route law applies to generation and automatic changes; player carve/fill edits remain unrestricted.
+This is standalone Core evidence; it is not yet connected to the season asset/hash path or reviewed in
+the owner's game.
+
 ## 9. Multiplayer model (listen-server first, dedicated-friendly)
 
 > **Status: transport is DESIGN ONLY — nothing is networked in-tree yet** (no `Replicated`/`HasAuthority`/RPCs; a