feat: scale village queries and enrich Jajce center

docs/ARCHITECTURE_OVERVIEW.md

@@ -10,6 +10,7 @@ results.
 ```text
 SimulationClock
     -> SimulationManager orchestrates one deterministic tick
+        -> SimulationPopulationView indexes all/living/starving NPCs by stable ID
         -> ActionExecutionSystem advances needs and work
         -> VillageOpportunitySystem re-derives the current capable helper
         -> ActionSelectionSystem chooses an action
@@ -42,6 +43,10 @@ would otherwise obscure that lifecycle:
   first without weakening its direct-source or one-hop checks;
 - `simulation/relationships/RelationshipSystem.gd` owns directed relationship
   queries, event-driven trust changes, and deterministic social tie-breaking;
+- `simulation/population/SimulationPopulationView.gd` owns a transient derived
+  all/living/starving stable-ID index. The manager rebuilds it once at the tick
+  boundary and refreshes it after each interleaved NPC update; relationship and
+  action queries may read it, but it never enters save records;
 - `simulation/opportunities/VillageOpportunitySystem.gd` observes immutable
   event references plus current NPC/storage state, then owns the bounded shared
   open/resolved/invalidated lifecycle for the proven pantry-food and blocked-
@@ -76,6 +81,7 @@ hard to read.
 | `simulation/events/` | Immutable event history and derived event queries |
 | `simulation/knowledge/` | Per-NPC knowledge of objective event IDs |
 | `simulation/relationships/` | Directed social consequences and relationship queries |
+| `simulation/population/` | Transient per-tick population query indexes |
 | `simulation/opportunities/` | Knowledge-gated unresolved-condition projections |
 | `simulation/state/` | Versioned, serializable mutable records |
 | `simulation/definitions/` | Stable IDs and immutable gameplay definitions |
@@ -118,6 +124,12 @@ improving ownership.
 - Benchmark fixtures use ordinary simulation records and must round-trip
   through the current state schema. They may control workload setup, but must
   not add benchmark-only fields or branches to production saves and ticks.
+- Derived population indexes are disposable acceleration structures. NPC
+  records remain authoritative, and rebuilding the view after initialization,
+  restore, or a tick must produce the same decisions and checksum.
+- Camera-local grass, ambient butterflies, water animation, smoke, and foliage
+  motion are presentation only. Grass consumes bounded real actor transforms;
+  it does not write NPC positions or become persistent state.
 - Opportunity records reference stable NPC, storage, resource, trigger-event,
   and resolution-event IDs. Their generator may observe authoritative state
   and history, but it does not mutate the economy or command NPC behavior. The