feat(simulation): dialogue pipeline, ContentSlug, and walk-away KG recording

Implement full dialogue selection pipeline (D-028): 4-layer filtering
engine with access tier, situation derivation, trust tier, and weighted
topic+mood scoring via SimRng. Add ContentSlug component for stable
content identity across save/load. Add walk-away KG recording with
IncompleteInteraction events per D-064 three-phase consequences. Bump
protocol to v8 with DialogueResponseEvent. Fixes #305, #427, #452.

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

server/src/simulation/mod.rs

@@ -4,6 +4,7 @@
 use bevy_app::prelude::*;
 use bevy_ecs::schedule::IntoScheduleConfigs;
 
+pub mod dialogue;
 pub mod input;
 pub mod interaction;
 pub mod inventory;