Refactor the D&D spells module to apply deterministic fields where appropriate

internal/modules/extract/dnd/spells/assets/prompts/dnd.spells.yaml

@@ -32,5 +32,5 @@ messages:
 output:
   format: json
   validation_mode: json_schema
-  schema_path: dnd_spells.v1.json
+  schema_path: dnd_spells_llm.v1.json
   repair_attempts: 0

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

@@ -1,8 +1,9 @@
-Source references must use integer source-unit IDs from the transcript.
+Source references must use integer source-unit IDs from the transcript. Provide
+start_unit_id and end_unit_id for each source reference; the extractor assigns
+source_id automatically.
 
 Return only D&D spell-cast artifacts. For each spell cast, identify the in-world
-caster, spell name, effect, narrative description, and source references using
-source_id, start_unit_id, and end_unit_id.
+caster, spell name, effect, narrative description, and source references.
 
 Use player, party, and glossary reference material only to clarify source text.
 Do not return spells, casters, or effects that are mentioned only in reference

internal/modules/extract/dnd/spells/assets/schemas/dnd_spells_llm.v1.json

@@ -0,0 +1,60 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "notarius.dnd.spells.llm",
+  "type": "object",
+  "additionalProperties": false,
+  "required": ["spell_casts"],
+  "properties": {
+    "spell_casts": {
+      "type": "array",
+      "items": {
+        "type": "object",
+        "additionalProperties": false,
+        "required": [
+          "caster",
+          "spell",
+          "effect",
+          "narrative_description",
+          "source_refs"
+        ],
+        "properties": {
+          "caster": {
+            "type": "string",
+            "minLength": 1
+          },
+          "spell": {
+            "type": "string",
+            "minLength": 1
+          },
+          "effect": {
+            "type": "string",
+            "minLength": 1
+          },
+          "narrative_description": {
+            "type": "string",
+            "minLength": 1
+          },
+          "source_refs": {
+            "type": "array",
+            "minItems": 1,
+            "items": {
+              "type": "object",
+              "additionalProperties": false,
+              "required": ["start_unit_id", "end_unit_id"],
+              "properties": {
+                "start_unit_id": {
+                  "type": "integer",
+                  "minimum": 1
+                },
+                "end_unit_id": {
+                  "type": "integer",
+                  "minimum": 1
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+}