Harden the state-emit rule to reduce under-reporting

Rewrite the global emit rule to be directive: treat narration as
authoritative and record numeric changes (damage, healing, time, emotion
shifts, fights intensifying), not just easy on/off flags — updating every
stat the scene affected. Also firm up the demo scenario's AI instructions
to reflect combat outcomes in the numbers each turn. Helps weaker free
models emit numeric deltas; the emit rule applies live so all RPG
adventures benefit immediately.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/app/seed_data/04-rpg-world-state.json

@@ -4,7 +4,7 @@
   "prompt": "Dawn breaks grey over the treeline as you and Gwen crouch at the edge of the bandit camp. Smoke curls from a dying fire; three bedrolls lie empty. Somewhere ahead, the stolen caravan strongbox waits.\n\nGwen checks her bowstring and looks to you. \"Quiet, or loud?\"",
   "memory": "The player and Gwen, a loyal ranger ally, are raiding a bandit camp to recover a stolen strongbox. The player is a capable adventurer. This is a dangerous but winnable encounter.",
   "authors_note": "Keep it tense and consequential. Reckless moves should cost health; clever ones should pay off. Gwen reacts to how the player treats her.",
-  "ai_instructions": "Write in second person, present tense. End each reply where the player can act. Let the world state guide the fiction — if the player is badly hurt, show it.",
+  "ai_instructions": "Write in second person, present tense. End each reply where the player can act. Let the world state guide the fiction — if the player is badly hurt, show it. In any fight, reflect the outcome in the numbers every turn: reduce the health of whoever is struck, raise the bandit leader's aggression as he is pressed, and adjust Gwen's trust based on how the player treats her.",
   "tags": "demo, rpg, world-state, combat, short",
   "stat_schema": {
     "world": {

backend/app/worldstate/engine.py

@@ -19,14 +19,18 @@ STAT_SECTIONS = ("world", "player")
 
 # Appended once to the system prompt so the model knows how to report changes.
 EMIT_RULE = (
-    "After your narration, if and ONLY IF something in the world state changed this "
+    "You maintain a numeric world state. Treat your own narration as authoritative: "
-    "turn, append a fenced code block labelled `state` containing a JSON object of "
+    "whenever what you write implies a change — someone takes damage or heals, time "
-    "the CHANGES ONLY, as deltas (not new totals). Use paths like "
+    "passes, an emotion or relationship shifts, a fight intensifies, an item is gained "
-    '"player.hp", "world.day", "npc.<id>.<stat>" (use the exact npc id shown in the '
+    "or lost, or an objective is completed — you MUST record it, including the numbers, "
-    'world state, e.g. npc.gwen.trust); "flags.<name>": true or false to toggle an '
+    "not just on/off flags. After your narration, append a fenced code block labelled "
-    'on/off state; and "milestones.<id>": true when an objective is completed. Send '
+    "`state` with a JSON object of the CHANGES ONLY, as deltas (not new totals). Update "
-    "only things that actually changed; never restate unchanged values. If nothing "
+    "every stat the scene affected this turn, not only the easy ones. Use the paths "
-    "changed, omit the block entirely. Example:\n"
+    'exactly as shown in the world state: "player.hp", "world.day", "npc.<id>.<stat>" '
+    '(e.g. npc.gwen.trust — use the id in parentheses, not the display name); '
+    '"flags.<name>": true or false to toggle an on/off state; and "milestones.<id>": '
+    "true when an objective is completed. Send only things that actually changed and "
+    "never restate unchanged values; if truly nothing changed, omit the block. Example:\n"
     '```state\n{"player.hp": -15, "npc.gwen.trust": 5, "milestones.escaped": true}\n```'
 )