V1.8.0: the fallen are hidden, and allies can revive the dead

- A dead character, or a monster or NPC at 0 HP, is out of the fight: the
  server no longer sends it to players, target marks included, and it has
  no turn. Healing or reviving brings it straight back.
- The DM's screen leaves the fallen out too until "Show dead" is ticked,
  which lists them in a group of their own, marked hidden.
- Players see dead characters by name in a Fallen box. The player whose
  character is on turn in a battle gets "Try revive" there if that
  character is on their feet and knows a spell that revives, at a level
  they can cast. The dead come back at 1 HP.
- Spells have a "Revives" tick in the campaign's spell list. Revivify and
  Raise Dead have it, in the library and in existing campaigns.
- A dead character cannot be added to an encounter until revived.
- All packages at version 1.8.0.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

package-lock.json

@@ -1,19 +1,19 @@
 {
   "name": "dnd-campaign-manager",
-  "version": "1.7.2",
+  "version": "1.8.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "dnd-campaign-manager",
-      "version": "1.7.2",
+      "version": "1.8.0",
       "workspaces": [
         "backend",
         "frontend"
       ]
     },
     "backend": {
-      "version": "1.7.2",
+      "version": "1.8.0",
       "dependencies": {
         "@prisma/client": "^5.20.0",
         "bcrypt": "^5.1.1",
@@ -31,7 +31,7 @@
       }
     },
     "frontend": {
-      "version": "1.7.2",
+      "version": "1.8.0",
       "dependencies": {
         "@tanstack/react-query": "^5.103.2",
         "axios": "^1.20.0",