fix: prevent pre-existing event notifications on group join

joinedAt was stored on the group record, but foregroundSync and
resyncGroup overwrote it from the Autobase view (which has no
joinedAt). Now joinedAt is persisted as a dedicated Hyperbee key
(joinedAt:{groupId}) that survives all group record writes.

Also preserves joinedAt on group record in foregroundSync/resyncGroup
for member-filtering logic, updates iOS build instructions to prevent
bundle caching issues (--checksum rsync, sim bundle sync).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CLAUDE.md

@@ -64,7 +64,7 @@ ssh Tims-Mac-mini.local 'security unlock-keychain -p "" ~/Library/Keychains/buil
 npx esbuild src/ui/main.jsx --bundle --format=iife --jsx=automatic \
   --define:process.env.NODE_ENV=\"production\" --outfile=assets/app-ui.bundle
 # 2. Sync, build, package, install
-rsync -az --exclude='.git' --exclude='node_modules' --exclude='android' \
+rsync -az --checksum --exclude='.git' --exclude='node_modules' --exclude='android' \
   /home/tim/peerloomllc/pearcal-native/ \
   Tims-Mac-mini.local:~/peerloomllc/pearcal-native/
 ssh Tims-Mac-mini.local 'export PATH="/opt/homebrew/bin:$PATH" && export LANG=en_US.UTF-8 && \
@@ -84,6 +84,7 @@ ideviceinstaller install /tmp/PearCal-release.ipa
 ```bash
 node_modules/.bin/bare-pack --linked src/bare.js -o assets/bare-universal.bundle
 node_modules/.bin/bare-pack --host ios-arm64 --linked src/bare.js -o assets/bare-ios.bundle
+cp assets/bare-ios.bundle assets/bare-ios-sim.bundle
 npx esbuild src/ui/main.jsx --bundle --format=iife --jsx=automatic \
   --define:process.env.NODE_ENV=\"production\" --outfile=assets/app-ui.bundle
 # Then sync + build as above
@@ -91,7 +92,7 @@ npx esbuild src/ui/main.jsx --bundle --format=iife --jsx=automatic \
 
 **Swift/native module changes** (also runs `pod install` first):
 ```bash
-rsync -az --exclude='.git' --exclude='node_modules' --exclude='android' \
+rsync -az --checksum --exclude='.git' --exclude='node_modules' --exclude='android' \
   /home/tim/peerloomllc/pearcal-native/ \
   Tims-Mac-mini.local:~/peerloomllc/pearcal-native/
 ssh Tims-Mac-mini.local 'export PATH="/opt/homebrew/bin:$PATH" && export LANG=en_US.UTF-8 && \
@@ -107,6 +108,8 @@ rsync -az Tims-Mac-mini.local:/tmp/PearCal-release.ipa /tmp/
 ideviceinstaller install /tmp/PearCal-release.ipa
 ```
 
+**iOS bundle caching:** Expo's asset cache survives install-over-top. If iOS behaves differently than expected after a deploy, do a full uninstall first: `ideviceinstaller uninstall com.pearcal` (this wipes app data). Also always keep `bare-ios-sim.bundle` in sync with `bare-ios.bundle` and use `--checksum` with rsync.
+
 **Note:** New Swift/`.m` files must be registered in `PearCal.xcodeproj/project.pbxproj` via the `xcodeproj` Ruby gem before building. See plan tasks for the helper script.
 
 **Release (App Store):** Archive and export from Xcode on the Mac Mini. Increment `buildNumber` in `app.json` before each upload.

src/bare.js

@@ -287,6 +287,7 @@ async function reinviteMember (groupId, memberId) {
 
 async function deleteGroup (id) {
   await db.del(NS.groups + id)
+  await db.del('joinedAt:' + id).catch(() => {})
   // Clean up member records
   for await (const { key } of db.createReadStream({ gt: NS.members + id, lt: NS.members + id + '\xff' })) {
     await db.del(key)
@@ -342,6 +343,13 @@ const pendingMemberLeaves = new Set()  // {groupId,memberId} JSON strings, pendi
 async function joinGroup (group) {
   if (bases.has(group.id)) return
 
+  // Persist joinedAt as a dedicated key so it survives group record overwrites
+  const joinedAtKey = 'joinedAt:' + group.id
+  const existingJoin = await db.get(joinedAtKey).catch(() => null)
+  if (!existingJoin) {
+    await db.put(joinedAtKey, { ts: group.joinedAt || Date.now() })
+  }
+
   console.log('Joining group swarm:', group.id)
 
   const profile = await getProfile()
@@ -563,6 +571,7 @@ async function foregroundSync () {
             name:  gNode.value.name  || lv?.name,
             emoji: gNode.value.emoji || lv?.emoji,
             icon:  gNode.value.icon  ?? lv?.icon,
+            joinedAt: lv?.joinedAt || gNode.value.joinedAt,
             nickname: lv?.nickname || gNode.value.nickname,
           })
           send({ type: 'event', event: 'sync', data: groupId })
@@ -635,6 +644,7 @@ async function resyncGroup (groupId) {
           name:    value.name    || ev?.name,
           emoji:   value.emoji   || ev?.emoji,
           icon:    value.icon    ?? ev?.icon,
+          joinedAt: ev?.joinedAt || value.joinedAt,
           removedMembers: [...removedMap.values()],
           members: [...mergedMap.values()]
         })
@@ -798,8 +808,8 @@ function makeApply (groupId) {
             const eventDate = val.value.date
             if (eventDate && eventDate < new Date().toISOString().slice(0, 10)) continue
             // Skip notifications for events that predate our join (initial sync flood)
-            const localGroupJoin = await db.get(NS.groups + groupId).catch(() => null)
-            const joinedAt = localGroupJoin?.value?.joinedAt ?? 0
+            const joinNode = await db.get('joinedAt:' + groupId).catch(() => null)
+            const joinedAt = joinNode?.value?.ts ?? 0
             if (joinedAt && val.value.updatedAt && val.value.updatedAt < joinedAt) continue
             // Skip notification if only color changed
             const onlyColorChanged = localPrev &&