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/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>,