refactor(simulation): remove v0.1 content loading system (#655)

Delete the hand-authored YAML content pipeline (server/src/content/) superseded
by the v0.2 generator-first approach (D-122, D-128). Runtime ECS types that were
co-located with content loading have been extracted to dedicated simulation modules:

- simulation/triangle.rs: TriangleState, TriangleCrisisEventQueue, tick/resolve systems
- simulation/line_pool.rs: LinePoolIndex, AccessTier, TrustTier, Mood, LinePoolIndexResource
- simulation/knowledge_grant.rs: KnowledgeGrant, Prerequisites

Monologue systems (trigger_monologue, trigger_recognition_monologue,
trigger_event_monologue) now use hardcoded fallback lines only; the
ContentStoreResource branch and select_pool_line function are removed.

Deleted: content/{loader,types,line_pool,hot_reload,spawn,instantiation,entanglement,mod}.rs
Deleted: tests/{content_loading,content_runtime,content_scaling,template_instantiation,template_schema}.rs
Deleted: bin/line_preview.rs (v0.1 tool)

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

server/src/simulation/save_io.rs

@@ -16,7 +16,7 @@ use thiserror::Error;
 
 use crate::bridge::types::SaveLoadResultWire;
 use crate::bridge::types::SnapshotBuffer;
-use crate::content::template::{TemplateReferenceMap, TriangleState};
+use crate::simulation::triangle::{TemplateReferenceMap, TriangleState};
 use crate::knowledge::graph::KnowledgeGraph;
 use crate::knowledge::registry::EntityRegistry;
 use crate::npc::Npc;
@@ -30,7 +30,7 @@ use crate::knowledge::types::StableId;
 use crate::simulation::interaction::DoorState;
 use crate::simulation::tier::{ActiveSim, BackgroundSim};
 use crate::simulation::time::SimulationTime;
-use crate::content::template::TriangleCrisisEventQueue;
+use crate::simulation::triangle::TriangleCrisisEventQueue;
 use crate::storyteller::{
     ActivationState, ContaminationActive, ContaminationEventQueue, MovementHistoryBuffer,
     TriangleActivatedQueue,
@@ -594,7 +594,7 @@ mod tests {
 
     #[test]
     fn load_from_file_rejects_wrong_format_version() {
-        use crate::content::template::TemplateReferenceMap;
+        use crate::simulation::triangle::TemplateReferenceMap;
         // Craft a save with a wrong format_version
         let bad_state = SaveStateV1 {
             format_version: 0xFF, // deliberately wrong
@@ -775,7 +775,7 @@ mod tests {
     // -----------------------------------------------------------------------
 
     fn make_test_triangle(slug: &str, tension: u8) -> TriangleState {
-        use crate::content::template::{
+        use crate::simulation::triangle::{
             RoleId, TemplateId, TriangleClassification, TriangleId, TrianglePhase,
         };
         let mut role_assignments = std::collections::BTreeMap::new();