fix(server): address PR #14 review — ordering, docs, version pin

- Fix NpcPlugin system ordering: .before(compute_paths) instead of
  .after(advance_tick) so PathRequests are picked up same frame
- Fix stale doc comment in interpretation.rs: system runs BEFORE
  knowledge events, not after
- Add TODO(v0.2) on RelationshipGraph about information boundary
  limitation for multiplayer
- Document cardinal-only movement as deliberate v0.1 choice
- Add comment on manhattan_distance u32::MAX fallback for cross-z
- Pin pathfinding crate to 4.11

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

server/Cargo.toml

@@ -11,7 +11,7 @@ rmp-serde = "1"
 bincode = "1"
 rand = "0.9"
 rand_chacha = "0.9"
-pathfinding = "4"
+pathfinding = "4.11"
 thiserror = "2"
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }

server/src/npc/mod.rs

@@ -25,7 +25,7 @@ impl Plugin for NpcPlugin {
             .add_systems(
                 Update,
                 routine::check_phase_transition
-                    .after(crate::simulation::time::advance_tick),
+                    .before(crate::simulation::pathfinding::compute_paths),
             );
 
         tracing::debug!("NpcPlugin initialized");

server/src/npc/relationships.rs

@@ -25,6 +25,12 @@ pub struct RelationshipEdge {
 /// Global relationship graph resource.
 /// BTreeMap<(subject, target), edge> for deterministic iteration (D-010).
 /// Directed graph: edge (A, B) represents how A feels about B.
+///
+/// TODO(v0.2): This is a global omniscient resource — all entities share one
+/// graph. This violates information boundaries (D-009/D-010) because any
+/// system can read any relationship. For multiplayer, this needs per-observer
+/// projection so each entity only sees relationships they should know about.
+/// Acceptable for v0.1 single-player where the server is authoritative.
 #[derive(Resource, Debug, Clone, Default, Serialize, Deserialize)]
 pub struct RelationshipGraph {
     edges: BTreeMap<(StableId, StableId), RelationshipEdge>,

server/src/perception/interpretation.rs

@@ -68,7 +68,8 @@ impl ObservationEventQueue {
 
 /// System: interpret visible snapshot against known routines and knowledge.
 ///
-/// Runs after knowledge events are processed so the knowledge graph is up-to-date.
+/// Runs BEFORE knowledge events are processed so it can detect new entities
+/// by comparing visible NPCs against the previous tick's knowledge state.
 /// Produces observation events for: routine deviations, absences, new entities.
 pub fn generate_observation_events(
     time: Res<SimulationTime>,

server/src/simulation/pathfinding.rs

@@ -55,6 +55,8 @@ pub struct PathBlocked;
 
 /// System: compute paths for entities with PathRequest components.
 /// Uses A* over the WalkabilityMap with cardinal movement (4 neighbors).
+/// Cardinal-only is a deliberate v0.1 simplification: diagonal movement
+/// would require √2 cost handling and diagonal wall-clipping checks.
 /// Removes PathRequest and inserts ComputedPath or PathBlocked.
 pub fn compute_paths(
     mut commands: Commands,
@@ -90,6 +92,8 @@ pub fn compute_paths(
                     .filter(|neighbor| walkability.can_move_to(neighbor))
                     .map(|neighbor| (neighbor, 1u32))
             },
+            // manhattan_distance returns None for cross-z-level pairs;
+            // u32::MAX makes A* deprioritize those nodes (v0.1: single z-level)
             |pos| pos.manhattan_distance(&goal).unwrap_or(u32::MAX),
             |pos| *pos == goal,
         );