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/track.post.js

@@ -2,6 +2,7 @@ import { requireAuth } from '../../utils/auth.js'
 import { validateBody } from '../../utils/validateBody.js'
 import { onboardingTrackSchema } from '../../utils/schemas.js'
 import Member from '../../models/member.js'
+import BoardPost from '../../models/boardPost.js'
 import { logActivity } from '../../utils/activityLog.js'
 
 export default defineEventHandler(async (event) => {
@@ -26,22 +27,24 @@ export default defineEventHandler(async (event) => {
   // Log the individual goal completion
   await logActivity(member._id, 'member_onboarding_goal_completed', { goal }, { visibility: 'admin' })
 
+  // Must have at least one board post to graduate
+  const hasPosted = await BoardPost.exists({ author: member._id })
+
   // Graduation check — atomic so concurrent requests can't double-graduate
-  const graduated = await Member.findOneAndUpdate(
-    {
-      _id: member._id,
-      'onboarding.completedAt': null,
-      'onboarding.eventPageVisited': true,
-      'onboarding.boardPageVisited': true,
-      'onboarding.wikiClicked': true,
-      'craftTags.0': { $exists: true },
-      'board.topics': {
-        $elemMatch: { state: { $in: ['help', 'interested', 'seeking'] } },
-      },
-    },
-    { $set: { 'onboarding.completedAt': new Date() } },
-    { new: true }
-  )
+  const graduated = hasPosted
+    ? await Member.findOneAndUpdate(
+        {
+          _id: member._id,
+          'onboarding.completedAt': null,
+          'onboarding.eventPageVisited': true,
+          'onboarding.boardPageVisited': true,
+          'onboarding.wikiClicked': true,
+          'craftTags.0': { $exists: true },
+        },
+        { $set: { 'onboarding.completedAt': new Date() } },
+        { new: true }
+      )
+    : null
 
   if (graduated) {
     await logActivity(member._id, 'member_onboarding_completed', {}, { visibility: 'admin' })