feat: carve Jajce river into terrain

docs/BUILD_IN_PUBLIC_PLAN.md

@@ -774,17 +774,23 @@ Completed:
     stable-ID resource anchors in a resource-specific horizontal grid. Exact
     expanding queries preserve current scoring and selected targets while the
     reviewed 1,800-source case inspects about 4.4 candidates instead of 1,800.
+36. `Jajce River 03`: the deterministic Terrain3D source now carves a raised
+    waterfall shelf, upper stream, plunge basin, and curved downstream channel.
+    Shared watercourse profiles keep generated terrain and both water ribbons
+    aligned; softened foam/mist and a smaller rock frame make the falls part of
+    the landform. A matched Metal capture records the change, and the rebaked
+    navigation mesh passes terrain-height and runtime route checks.
 
 Next:
 
-1. Sculpt a real Terrain3D river channel and waterfall shelf before adding a
-   broad foliage asset pass. Use Terrain3D particles for nearby grass and
-   intentional instancing for tree/fern/rock masses, then rebake and validate
-   the required village/resource routes.
-2. During that first larger foliage pass, prove a bounded authoring workflow
-   that places intentional stable-ID `ResourceNode` anchors beside decorative
-   Terrain3D instances. Add livestock only with a real identity and interaction
-   contract.
+1. Prove one bounded foliage/resource authoring workflow at a riverbank or
+   forest edge. Use decorative Terrain3D/intentional instances for tree, fern,
+   flower, and rock masses, but create simulation-owned finite resources only
+   through selected stable-ID `ResourceNode` anchors.
+2. Validate that villagers discover both nearby and farther authored anchors,
+   preserve reachable interaction points, and keep the visual batch inside a
+   measured presentation budget. Add livestock only with a real identity and
+   interaction contract.
 
 Do not start with GIS data, a full city, a large asset pack, or more NPC
 mechanics. The next proof is a beautiful stage for the systems that already

docs/LEARNING_ROADMAP.md

@@ -889,15 +889,29 @@ Unload/rebind state authority, stable tie order, moved anchors, reservations,
 player parity, and a deliberately far high-priority winner remain covered. See
 [Loaded Resource Discovery 01](benchmarks/LOADED_RESOURCE_DISCOVERY_01.md).
 
-The immediate next slice should pair this systems foundation with the authored
-world: sculpt the real Terrain3D river channel and waterfall shelf, rebake and
-validate navigation, then use the first larger foliage/resource pass to prove a
-bounded stable-ID anchor placement workflow alongside decorative Terrain3D
-instancing. Do not generalize the resource grid to people/buildings/events or
+The authored-watercourse slice is complete. `JajceWatercourse` now gives the
+deterministic terrain generator and both water ribbons one shared profile; the
+generated Terrain3D data contains an upper stream, raised waterfall shelf,
+plunge basin, and curved downstream channel. A matched Metal capture records
+the result, and the Terrain3D-derived navigation mesh was rebaked and validated
+against required village/resource routes.
+
+The immediate next slice should prove one bounded foliage/resource authoring
+workflow in the real world: build a restrained riverbank or forest-edge cluster
+with decorative Terrain3D/intentional instances, pair only selected harvestable
+trees or berry patches with stable-ID `ResourceNode` anchors, and verify nearby
+and farther loaded anchors remain discoverable through `ActiveWorldAdapter`.
+Keep decorative instances out of simulation state, measure the bounded visual
+cost, and do not generalize the resource grid to people/buildings/events or
 introduce active/abstract LOD before those consumers need it.
 
 Recently completed:
 
+- `Jajce River 03`: deterministic Terrain3D generation now carves the upper
+  stream, raised waterfall shelf, plunge basin, and curved downstream channel;
+  shared watercourse geometry keeps both water ribbons aligned, soft masked
+  mist replaces hard billboards, and the rebaked navigation mesh passes
+  terrain-height and runtime resource-route checks.
 - Loaded-resource spatial discovery: a resource-specific active-world grid
   preserves exact score winners and lifecycle authority while reducing the
   reviewed 1,800-anchor query from 6.45 ms to 46.94 µs.

docs/PROJECT_CONTEXT.md

@@ -341,8 +341,9 @@ but retain far sources whenever their authoritative metadata can still win.
 
 - a centered 512 m Terrain3D landscape split across four regions;
 - deterministic shaped terrain data and six game-owned surface layers;
-- a larger summit citadel, eight cascading houses, mill, full-span bridge,
-  rock-framed waterfall, mist, smoke, and a Terrain3D-sampled river ribbon;
+- a larger summit citadel, eight cascading houses, mill, full-span bridge, and
+  a deterministic Terrain3D watercourse with an upper stream, raised waterfall
+  shelf, rock-framed drop, plunge basin, mist, and curved downstream ribbon;
 - authored dirt path strips that make the current village task loop readable;
 - compact silhouette props for the ridge landmark, guard, study, and rest
   sites, plus a physical pantry whose empty/low/stocked arrangement follows
@@ -979,10 +980,12 @@ Raw samples and workload exclusions live in
 [Simulation scaling baseline 02](benchmarks/SIMULATION_SCALING_BASELINE_02.md)
 and [Loaded Resource Discovery 01](benchmarks/LOADED_RESOURCE_DISCOVERY_01.md).
 
-The next slice should return to the authored Jajce stage: sculpt the real
-Terrain3D river channel and waterfall shelf, rebake/validate navigation, and
-use the following foliage expansion to prove a bounded stable-ID resource
-anchor placement workflow beside decorative Terrain3D instances. Do not yet
+The authored Jajce watercourse and its Terrain3D-derived navigation rebake are
+complete. The next slice should prove a bounded stable-ID resource-anchor
+placement workflow beside decorative Terrain3D/intentional foliage instances
+at one riverbank or forest edge. It should validate nearby and farther loaded
+resource discovery, reachable interaction points, and a measured presentation
+budget without making decorative instances authoritative. Do not yet
 generalize the resource grid or introduce active/abstract simulation LOD.
 
 The remaining simulation-garden target still aims for:

docs/baselines/JAJCE_RIVER_03.md

@@ -0,0 +1,80 @@
+# Jajce River 03
+
+Captured: 2026-07-17
+
+## Files
+
+- [before overview](jajce_river_03_before.png)
+- [after overview](jajce_river_03_after.png)
+- `tools/capture_jajce_lookdev.gd`
+- `tools/generate_jajce_terrain.gd`
+- `tools/bake_jajce_navigation.gd`
+
+The images use the same 1280×720 camera, fixed daylight value, warmup, and
+Metal renderer. They are a matched checkpoint rather than two independently
+composed beauty shots.
+
+## What changed
+
+The previous river was a turquoise presentation ribbon laid across a mostly
+flat valley. Its waterfall was held by a large freestanding rock frame, so the
+water feature read more like a prop than part of the landscape.
+
+The deterministic Terrain3D source now creates:
+
+- a raised shelf upstream of the falls;
+- a shallow upper stream widening toward the lip;
+- an approximately 12 m drop into a shaped plunge basin;
+- a curved downstream channel with visible banks; and
+- slope-driven rock texture around the drop and steeper channel edges.
+
+The waterfall frame is smaller and nested into that landform. Its foam is more
+restrained, and the mist uses a soft radial mask so individual particle quads
+do not appear against the dark cliff. The result remains deliberately reduced:
+citadel, roofs, shelf, falls, bridge, and river form one readable village-center
+composition without attempting a literal reconstruction of Jajce.
+
+## Deterministic authoring contract
+
+`JajceWatercourse` owns the shared center lines, widths, bed heights, shelf
+height, and water offset. `generate_jajce_terrain.gd` uses that profile to
+produce the checked-in Terrain3D regions; `TerrainRiverRibbon.gd` uses the same
+profile and samples the generated terrain for both water meshes. Changing the
+watercourse therefore has one explicit regeneration and navigation-rebake
+path instead of unrelated hand-tuned terrain and presentation coordinates.
+
+This is presentation and interaction geometry only. No resource IDs,
+simulation records, RNG streams, save data, or NPC decision rules changed.
+
+## Validation
+
+The focused watercourse scenario records an upper-stream height of 11.28 m, a
+12.43 m shelf bank, and a -0.65 m plunge basin. It also checks multiple points
+along the downstream bed and verifies both generated water ribbons remain
+within 3 cm of the Terrain3D surface plus the shared water offset.
+
+The navigation bake now contains 403 vertices and 620 polygons. The Jajce
+scaffold verifies required paths reach their destinations and track the new
+terrain heights, while the runtime integration scenario still completes real
+player resource gathering with all 18 finite resource anchors loaded.
+
+## Next visual/system proof
+
+The next pass should author one bounded riverbank or forest-edge foliage mass,
+using decorative Terrain3D/intentional instances for visual density and only a
+small selected set of stable-ID `ResourceNode` anchors for finite harvestable
+resources. Bank stones, ferns, flowers, and tree masses can improve the channel
+edge during that proof. Bridge, buildings, and fortress geometry remain
+prototype blockouts and should be replaced gradually rather than through a
+broad asset dump.
+
+## Capture command
+
+```bash
+HOME="$PWD/logs/quality/godot_profile" \
+APPDATA="$PWD/logs/quality/godot_profile" \
+LOCALAPPDATA="$PWD/logs/quality/godot_profile" \
+/Applications/Godot.app/Contents/MacOS/Godot \
+  --path "$PWD" --script res://tools/capture_jajce_lookdev.gd -- \
+  --output=res://docs/baselines/jajce_river_03_after.png
+```

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