Add D&D enemy event extractor

internal/modules/dnd/extract/enemyevents/assets/prompts/instructions.md

@@ -0,0 +1,14 @@
+Exclude party members, allies, neutral observers, mentioned-but-absent enemies,
+hazards, traps, environmental effects, uncertain allegiance, table talk,
+planning, hypotheses, recaps outside this passage, and downstream inference.
+
+Do not infer an engagement or outcome from initiative, turn absence, damage,
+defeat, movement, a scene ending, combat-opponent grounding, or any auxiliary
+artifact. Auxiliary inputs can guide attention but cannot prove or supply an
+event. Cite only narrow current-transcript ranges that establish each event.
+
+Return the `events` array even when no enemy event is established. Every event
+must contain only `name`, `kind`, and `source_refs`. Use exactly one kind:
+`engaged`, `killed`, `fled`, `captured`, or `incapacitated`. Each source range
+uses integer `start_unit_id` and `end_unit_id`; omit `source_id` because
+Notarius assigns the current source identity.