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>

client/data/ui-strings.yaml

@@ -125,6 +125,17 @@ knowledge_panel:
   confidence_medium: "Likely"
   confidence_low: "Unconfirmed"
   confidence_rumor: "Hearsay"
+  # D-041 KnowledgeConfidence levels — displayed in journal panel
+  confidence_direct: "Confirmed"
+  confidence_knowsdetails: "Detailed"
+  confidence_knowsof: "Known"
+  confidence_suspects: "Unconfirmed"
+  # D-041 KnowledgeSource labels — displayed in journal panel
+  source_directobservation: "Observed"
+  source_toldby: "Told"
+  source_heard: "Overheard"
+  source_inferred: "Inferred"
+  source_background: "Prior"
 
 # ============================================================
 # TUTORIAL TEXT (DIEGETIC)