feat(simulation): interaction tracking + trust progression (#325, #324)

InteractionMemory component tracks interaction_count, last_interaction_tick,
and notable_events per NPC. Drives D-028 Layer 2 situation activation:
first_meeting (count==0) and repeated_visit (count>=3). warm_active in mood
system now derives from InteractionMemory within a 300-tick window.

Trust progression wired into dialogue systems: talk completion (+1),
walk-away (-1), confrontation (-2) emit TrustEvents consumed by update_trust.
InteractionEvent (WalkAway, Confrontation) recorded in notable_events for
fast per-pair access.

Adds FirstMeeting and RepeatedVisit Situation variants. 18 unit tests in
interaction.rs. All arithmetic integer-only (D-010 determinism). No HashMap.

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

server/src/npc/mod.rs

@@ -2,6 +2,7 @@
 // Implements D-024: 10-axis NPC model + CombatCapability component
 // Background tier state machines for schedule, mood, relationships, job
 
+pub mod interaction;
 pub mod mood;
 pub mod relationships;
 pub mod routine;
@@ -22,6 +23,7 @@ pub struct NpcPlugin;
 impl Plugin for NpcPlugin {
     fn build(&self, app: &mut App) {
         app.init_resource::<relationships::RelationshipGraph>()
+            .init_resource::<relationships::TrustEventQueue>()
             .init_resource::<routine::PreviousDayPhase>()
             .add_systems(
                 Update,
@@ -31,6 +33,17 @@ impl Plugin for NpcPlugin {
                     mood::update_mood
                         .after(routine::check_phase_transition)
                         .before(crate::simulation::dialogue::process_talk_interaction),
+                    relationships::update_trust
+                        .after(crate::simulation::dialogue::process_talk_interaction)
+                        .after(crate::simulation::dialogue::process_walk_away)
+                        .after(crate::simulation::dialogue::process_confrontation_response)
+                        .before(crate::simulation::time::advance_tick),
+                    relationships::update_relationship_dynamics
+                        .after(relationships::update_trust)
+                        .before(crate::simulation::time::advance_tick),
+                    routine::enter_activity
+                        .after(crate::simulation::movement::validate_movement)
+                        .before(crate::perception::observer::compute_observer_snapshot),
                 ),
             );