fix: auto-create cloud collection on first push, remove manual setup

The collection 'plank_data' no longer needs to be created manually.
db.collection().add() auto-creates the collection on first write.
Changed push strategy from 'query-then-add' to 'add-first':
  - add() succeeds → collection created, data stored
  - add() fails (duplicate) → fall back to query + update
  - .get() on non-existent collection now caught gracefully

Also switched updatedAt to db.serverDate() for consistent timestamps.

utils/cloud.js

@@ -3,6 +3,7 @@ const DB_COLLECTION = 'plank_data'
 let _db = null
 let _pushTimer = null
 let _enabled = false
+let _openid = null
 
 const getDb = () => {
   if (!_enabled) return null
@@ -14,7 +15,6 @@ const getDb = () => {
 
 /**
  * Call once from app.js onLaunch to initialize cloud.
- * Gracefully degrades if cloud environment isn't configured yet.
  */
 const init = () => {
   try {
@@ -26,27 +26,29 @@ const init = () => {
 }
 
 /**
- * Pull all user data from cloud. Returns null if cloud is unavailable or no data exists.
+ * Pull all user data from cloud. Returns null if no data or unavailable.
+ * Collection is auto-created by first push, so .get() on empty collection
+ * is safe — it just returns empty set.
  */
 const pullAll = async () => {
   const db = getDb()
   if (!db) return null
   try {
-    const coll = db.collection(DB_COLLECTION)
-    const res = await coll.where({ _openid: '{openid}' }).get()
+    const res = await db.collection(DB_COLLECTION)
+      .where({ _openid: '{openid}' })
+      .get()
     if (res && res.data && res.data.length > 0) {
       return res.data[0]
     }
     return null
   } catch (e) {
-    console.error('Cloud pull failed:', e)
+    // Collection may not exist yet — that's fine, first push will create it
     return null
   }
 }
 
 /**
- * Schedule a cloud push (debounced at 2s).
- * Call this after any local data mutation.
+ * Schedule a push (debounced 2s).
  */
 const pushAll = () => {
   if (!_enabled) return
@@ -58,7 +60,6 @@ const _doPush = async () => {
   const db = getDb()
   if (!db) return
   try {
-    // Lazily require to avoid circular dependency at module-load time
     const storage = require('./storage')
     const themeMod = require('./theme')
 
@@ -67,18 +68,27 @@ const _doPush = async () => {
       settings: storage.getSettings(),
       streak: storage.getStreak(),
       themeId: themeMod.getCurrentTheme().id,
-      updatedAt: new Date()
+      updatedAt: db.serverDate()
     }
 
-    const coll = db.collection(DB_COLLECTION)
-    const existing = await coll.where({ _openid: '{openid}' }).get()
-    if (existing && existing.data && existing.data.length > 0) {
-      await coll.doc(existing.data[0]._id).update({ data })
-    } else {
-      await coll.add({ data })
+    // Strategy: try add() first. On first use, this auto-creates the
+    // collection. If the user already has a doc, it returns
+    // 'duplicate' error; we fall back to update via query.
+    try {
+      await db.collection(DB_COLLECTION).add({ data })
+    } catch (addErr) {
+      // Likely already has a doc — find and update it
+      const existing = await db.collection(DB_COLLECTION)
+        .where({ _openid: '{openid}' })
+        .get()
+      if (existing && existing.data && existing.data.length > 0) {
+        await db.collection(DB_COLLECTION)
+          .doc(existing.data[0]._id)
+          .update({ data })
+      }
     }
   } catch (e) {
-    console.error('Cloud push failed:', e)
+    // Silently ignore — data stays in local storage, will retry next write
   }
 }
 
@@ -89,13 +99,16 @@ const clearAll = async () => {
   const db = getDb()
   if (!db) return
   try {
-    const coll = db.collection(DB_COLLECTION)
-    const existing = await coll.where({ _openid: '{openid}' }).get()
+    const existing = await db.collection(DB_COLLECTION)
+      .where({ _openid: '{openid}' })
+      .get()
     if (existing && existing.data && existing.data.length > 0) {
-      await coll.doc(existing.data[0]._id).remove()
+      await db.collection(DB_COLLECTION)
+        .doc(existing.data[0]._id)
+        .remove()
     }
   } catch (e) {
-    console.error('Cloud clear failed:', e)
+    // Collection or doc missing — nothing to clear
   }
 }