refactor(board): delete old board routes, absorb slackHandle into profile PATCH

- Delete server/api/members/me/board.patch.js and server/api/board/suggestions.get.js
- Add boardSlackHandle to memberProfileUpdateSchema; remove boardPrivacy
- profile.patch.js: write boardSlackHandle -> board.slackHandle; drop boardPrivacy
- Remove privacy.board field from Member model
- onboarding/status.get.js: hasProfileTags now requires only craftTags; hasEngagedBoard uses BoardPost.exists
- onboarding/track.post.js: graduation check uses BoardPost.exists instead of board.topics elemMatch
- members/[id].get.js and directory.get.js: reduce board response to slackHandle only; drop connectionTag and peerSupport filters

server/api/onboarding/status.get.js

@@ -1,18 +1,16 @@
 import { requireAuth } from '../../utils/auth.js'
+import BoardPost from '../../models/boardPost.js'
 
 export default defineEventHandler(async (event) => {
   const member = await requireAuth(event)
 
-  const hasProfileTags =
-    member.craftTags.length > 0 &&
-    (member.board?.topics || []).length > 0
+  const hasProfileTags = member.craftTags.length > 0
 
   const hasVisitedEvent = !!member.onboarding?.eventPageVisited
 
-  const topics = member.board?.topics || []
+  const hasPosted = await BoardPost.exists({ author: member._id })
   const hasEngagedBoard =
-    !!member.onboarding?.boardPageVisited &&
-    topics.some((t) => ['help', 'interested', 'seeking'].includes(t.state))
+    !!member.onboarding?.boardPageVisited && !!hasPosted
 
   const hasClickedWiki = !!member.onboarding?.wikiClicked