fix: use object key for partial ID to match template reference

loadTemplates with an array registers the partial using the full file
path as its Handlebars ID (e.g.
'systems/fvtt-lethal-fantasy/templates/chat/_dice-breakdown.hbs'), but
the template references it by the short name 'chat/dice-breakdown'.
Using an object with explicit keys ensures the partial ID matches.

page3.txt

@@ -0,0 +1,26 @@
+uid=13_0 RootWebArea "Lethal Fantasy" url="https://localhost:31000/join"
+  uid=13_1 banner
+    uid=13_2 heading "Lethal Fantasy" level="1"
+  uid=13_3 form
+    uid=13_4 heading "Rejoindre la partie" level="2"
+    uid=13_5 combobox expandable haspopup="menu"
+      uid=13_6 option selectable selected
+      uid=13_7 option "Gamemaster" selectable value="Gamemaster"
+      uid=13_8 option "Player2" selectable value="Player2"
+    uid=13_9 textbox "Mot de passe"
+    uid=13_10 contentinfo
+      uid=13_11 button "REJOINDRE LA PARTIE"
+  uid=13_12 heading "Détails de la session" level="2"
+  uid=13_13 StaticText " Prochaine partie"
+  uid=13_14 StaticText " Joueurs présents"
+  uid=13_15 StaticText "0"
+  uid=13_16 StaticText "/"
+  uid=13_17 StaticText "2"
+  uid=13_18 form
+    uid=13_19 heading "Retour à l’accueil" level="2"
+    uid=13_20 StaticText "Vous êtes authentifié en tant qu’administrateur du serveur."
+    uid=13_21 contentinfo
+      uid=13_22 button "RETOUR À L’ACCUEIL"
+  uid=13_23 heading "Description du monde" level="2"
+  uid=13_24 contentinfo
+    uid=13_25 StaticText "Version 14 Build 364"