chore(pb): add discovery_votes collection to pb-init script

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

scripts/pb-init-v3.sh

@@ -259,6 +259,14 @@ create "translation_jobs" '{
     {"name":"heartbeat_at", "type":"date"}
   ]}'
 
+create "discovery_votes" '{
+  "name":"discovery_votes","type":"base","fields":[
+    {"name":"session_id","type":"text","required":true},
+    {"name":"user_id",   "type":"text"},
+    {"name":"slug",      "type":"text","required":true},
+    {"name":"action",    "type":"text","required":true}
+  ]}'
+
 # ── 5. Field migrations (idempotent — adds fields missing from older installs) ─
 add_field "scraping_tasks" "heartbeat_at"           "date"
 add_field "audio_jobs"     "heartbeat_at"           "date"