rename communityEcology → board across backend

Model, schemas, API routes, activity log, and all server handlers
updated. Old ecology/ and community-ecology routes removed, new
board/ routes added. Tests updated and new board-suggestions tests
written (10 cases).

app/utils/activityText.js

@@ -76,8 +76,8 @@ const formatters = {
     text: 'Updated community connections',
     icon: 'i-lucide-users'
   }),
-  community_ecology_updated: () => ({
-    text: 'Updated community ecology',
+  board_updated: () => ({
+    text: 'Updated board',
     icon: 'i-lucide-users'
   }),
   connection_requested: (m) => ({