refactor(community): rename Community Connections → Community Ecology

Simplify the feature to pure discovery (filter by topic, see matching
members, copy Slack handle). Drop the connection request/confirm flow
entirely — Connection model, 7 API endpoints, useConnections composable,
and TagInput component deleted.

- Rename communityConnections → communityEcology in schema, API, pages
- Delete legacy fields: offering, lookingFor, peerSupport
- New /ecology page, /api/ecology/suggestions, community-ecology.patch
- Nav: "Connections" → "Ecology", remove pending-count badge
- Fix auth/member.get.js missing craftTags + communityEcology
- Add community_ecology_updated activity log type
- Expose slackHandle conditionally when offerPeerSupport is true
- Add migration script at scripts/migrate-to-ecology.js (run before deploy)

server/models/activityLog.js

@@ -17,6 +17,7 @@ const ACTIVITY_TYPES = [
   'slack_invited',
   'email_sent',
   'community_connections_updated',
+  'community_ecology_updated',
   'connection_requested',
   'connection_confirmed',
   'tag_suggested'