fix(client): address PR #65 review — POI key, ToldBy parsing, KG dirty flag

- minimap.gd: fix "poi_category" → "category" key mismatch so POI
  colors and shapes render correctly
- journal_panel.gd: parse ToldBy(N) source format, resolve entity
  names from player_knowledge; move confidence/source labels to
  UIStrings per D-042
- observer/mod.rs: add Changed<KnowledgeGraph> dirty flag to skip
  per-tick KG serialization when unchanged
- types.rs: fix stale version doc comment (13 → 14)

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

server/src/bridge/types.rs

@@ -42,7 +42,7 @@ pub const PROTOCOL_VERSION: u8 = 14;
 /// Future fields: ambient sound events, HUD state (D-020 expansion).
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct ObserverSnapshot {
-    /// Protocol version for forward compatibility. Current: 13.
+    /// Protocol version for forward compatibility. Current: 14.
     pub version: u8,
     /// Simulation tick when this snapshot was produced
     pub tick: u64,