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)

app/composables/useEcology.js

@@ -0,0 +1,6 @@
+export const useEcology = () => {
+  const getSuggestions = (params = {}) =>
+    $fetch('/api/ecology/suggestions', { params })
+
+  return { getSuggestions }
+}