docs: establish simulation architecture gate

docs/RESOURCE_NODE_MIGRATION.md

@@ -112,7 +112,7 @@ type proves what is actually common.
 
 ## Fit with the current code
 
-The existing flow is:
+Before this migration, the flow was:
 
 ```text
 SimNPC chooses a task string
@@ -124,7 +124,7 @@ SimNPC chooses a task string
     -> SimVillage applies a hard-coded task result
 ```
 
-The migrated flow should become:
+The migrated flow is:
 
 ```text
 SimNPC chooses an action
@@ -139,15 +139,16 @@ SimNPC chooses an action
     -> reservation is released
 ```
 
-During migration:
+Current target behavior:
 
 ```text
-gather_food -> prefer matching ResourceNode -> fallback FarmZone
-gather_wood -> prefer matching ResourceNode -> fallback ForestZone
+gather_food -> matching ResourceNode -> recover/wander when unavailable
+gather_wood -> matching ResourceNode -> recover/wander when unavailable
 other tasks -> existing zones
 ```
 
-Fallbacks should log clearly so accidental reliance on zones is visible.
+Food and wood zone fallback was deliberately removed to preserve resource
+conservation.
 
 ## Repository-specific file layout
 
@@ -472,6 +473,12 @@ authoritative-yield rules.
 
 ### Phase 5 — Jajce world placement
 
+This phase is a bounded handoff to
+[the build-in-public visual plan](BUILD_IN_PUBLIC_PLAN.md), not permission for
+open-ended environment polish. Complete the scaffold, placement, and navigation
+proof, then pass the learning roadmap's architecture gate before the beauty
+baseline.
+
 - place bushes and trees as real world objects in `JajceWorld`;
 - keep their IDs stable;
 - validate interaction points against terrain and navigation;
@@ -516,7 +523,7 @@ At minimum, exercise:
 7. NPC dies while working;
 8. navigation fails;
 9. node is disabled while reserved;
-10. fallback zone is used because no matching node exists;
+10. no matching node causes recovery without zone production; ✅ implemented
 11. player and NPC contend for the same source; ✅ automated
 12. duplicate node IDs are detected.