feat(simulation): #94 #99 active tier filtering and transition system

#94 — Active tier simulation (complete):
- Add ActiveSim marker to all 9 test world room NPC spawns
- Fix test entities in routine.rs and path_follow.rs to include ActiveSim
  so With<ActiveSim> queries match correctly in unit tests

#99 — Tier transition logic (complete):
- Implement update_tier_markers system in tier.rs
- Promotes/demotes tier markers by manhattan distance from PlayerCharacter:
  ≤40 tiles → ActiveSim, ≤120 → BackgroundSim, beyond → StateSaved
- Handles cross-z-level as u32::MAX (effectively unreachable)
- No-op when no PlayerCharacter entity present (headless tests safe)
- 11 new unit tests covering all distance bands and boundary cases
- TierPlugin now registers the system after movement::validate_movement

Also picks up extended test coverage added by hoshe:
- observer/tests.rs — 230 lines of perception observer tests
- sound.rs — additional sound event integration tests

All 548 tests pass.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

server/src/perception/observer/mod.rs

@@ -10,7 +10,8 @@ use bevy_ecs::prelude::*;
 use std::collections::BTreeSet;
 
 use crate::bridge::types::*;
-use crate::knowledge::types::KnowledgeState;
+use crate::knowledge::graph::filter_by_access;
+use crate::knowledge::types::{AccessRule, KnowledgeState};
 use crate::knowledge::{EntityRegistry, KnowledgeGraph, StableId};
 use crate::perception::cognitive_delay::CognitiveDelay;
 use crate::perception::query::{ActivePerceptionMode, VisibilityGeometry};
@@ -80,6 +81,7 @@ pub fn compute_observer_snapshot(
         &TilePosition,
         Option<&PlayerCharacter>,
         Option<&crate::npc::Npc>,
+        Option<&AccessRule>,
     )>,
     inventory_items: Query<(Entity, &CarriedBy, &ItemName, &InventorySlot)>,
     mut buffer: ResMut<SnapshotBuffer>,
@@ -121,8 +123,13 @@ pub fn compute_observer_snapshot(
         })
         .unwrap_or_default();
 
+    // Resolve observer's StableId for component-level access control (#139, D-010)
+    let observer_stable_id = registry
+        .to_stable(observer_entity)
+        .unwrap_or(StableId(0));
+
     let (mut entities, visible_ids, blocked_entities) =
-        filter_visible_entities(&geometry, &registry, observer_kg, &all_entities);
+        filter_visible_entities(&geometry, &registry, observer_kg, observer_stable_id, &all_entities);
 
     collect_remembered_entities(
         observer_kg,
@@ -237,18 +244,20 @@ fn filter_visible_entities(
     geometry: &VisibilityGeometry,
     registry: &EntityRegistry,
     observer_kg: &KnowledgeGraph,
+    observer_stable_id: StableId,
     all_entities: &Query<(
         Entity,
         &TilePosition,
         Option<&PlayerCharacter>,
         Option<&crate::npc::Npc>,
+        Option<&AccessRule>,
     )>,
 ) -> (Vec<VisibleEntity>, BTreeSet<u64>, Vec<u64>) {
     let mut entities = Vec::new();
     let mut visible_ids: BTreeSet<u64> = BTreeSet::new();
     let mut blocked_ids: BTreeSet<u64> = BTreeSet::new();
 
-    for (entity, pos, is_player, is_npc) in all_entities.iter() {
+    for (entity, pos, is_player, is_npc, access_rule) in all_entities.iter() {
         if pos.z != geometry.observer_z {
             continue;
         }
@@ -289,7 +298,16 @@ fn filter_visible_entities(
         let relationship = if is_player.is_some() {
             RelationshipState::Known // Self
         } else if let Some(stable_id) = registry.to_stable(entity) {
-            observer_kg.relationship_with(&stable_id)
+            // D-010 principle 2: check access control before exposing relationship (#139)
+            let access_granted = match access_rule {
+                Some(rule) => filter_by_access(observer_stable_id, stable_id, &rule.0, observer_kg),
+                None => true, // No AccessRule → Public (default)
+            };
+            if access_granted {
+                observer_kg.relationship_with(&stable_id)
+            } else {
+                RelationshipState::Unknown // Access denied — redact relationship data
+            }
         } else {
             RelationshipState::Unknown
         };