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Delete the hand-authored YAML content pipeline (server/src/content/) superseded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/knowledge_grant.rs

@@ -0,0 +1,64 @@
+//! Knowledge grant types for dialogue and monologue lines.
+//!
+//! `KnowledgeGrant` describes the knowledge a player gains from a dialogue line.
+//! `Prerequisites` describes preconditions for a monologue line to fire.
+
+use serde::Deserialize;
+use std::collections::BTreeMap;
+
+/// Knowledge grant attached to a dialogue line (D-079).
+///
+/// Untagged enum — serde tries each variant in order:
+/// `Fact` matches YAML with `fact_id` field.
+/// `Entity` matches YAML with `entity_ref` field.
+#[derive(Debug, Clone, Deserialize)]
+#[serde(untagged)]
+pub enum KnowledgeGrant {
+    /// Grant knowledge of a non-entity fact.
+    /// Format: fact_id "category.topic", confidence string.
+    Fact {
+        fact_id: String,
+        confidence: String,
+    },
+    /// Grant knowledge of an entity (creates EntityKnowledge entry in observer's KG).
+    /// Required for contradiction detection: testimony must create ToldBy EntityKnowledge
+    /// so a subsequent DirectObservation can detect a discrepancy (D-079, D-083).
+    Entity {
+        entity_ref: String,
+        #[serde(default)]
+        attributes: BTreeMap<String, String>,
+        confidence: String,
+    },
+}
+
+/// Prerequisite set for a monologue line.
+#[derive(Debug, Clone, Deserialize)]
+pub struct Prerequisites {
+    #[serde(default)]
+    pub facts: Vec<FactPrerequisite>,
+    #[serde(default)]
+    pub entity_attributes: Vec<AttributePrerequisite>,
+    #[serde(default)]
+    pub relationship: Option<RelationshipPrerequisite>,
+}
+
+#[derive(Debug, Clone, Deserialize)]
+pub struct FactPrerequisite {
+    pub fact_id: String,
+    pub min_confidence: String,
+}
+
+#[derive(Debug, Clone, Deserialize)]
+pub struct AttributePrerequisite {
+    pub entity: String,
+    pub key: String,
+    pub value: String,
+}
+
+#[derive(Debug, Clone, Deserialize)]
+pub struct RelationshipPrerequisite {
+    #[serde(default)]
+    pub target: Option<String>,
+    #[serde(default)]
+    pub state: Option<String>,
+}