fix: read activity shards in GET /api/feed; improve sync feedback

_merged/index.json is a shard manifest with activities:[] when the user
has >FEED_PAGE_SIZE activities. The endpoint now collects from all
index-{year}.json shard files before returning.

SyncResult gains a `total` field (activities received from server) so the
feed screen can distinguish "server returned nothing" from "all already
stored locally". Messages: "No activities on instance" / "Up to date (N)"
/ "X of N activities synced".

bincio/serve/server.py

@@ -537,13 +537,24 @@ async def get_token(login_req: LoginRequest, request: Request) -> JSONResponse:
 
 @app.get("/api/feed")
 async def get_feed(user: User = Depends(_require_auth)) -> JSONResponse:
-    """Return the authenticated user's activity summaries (mobile feed sync)."""
+    """Return the authenticated user's activity summaries (mobile feed sync).
+
+    _merged/index.json is a shard manifest (activities: []) when the user has
+    more than FEED_PAGE_SIZE activities.  Collect from all shard files.
+    """
     dd = _get_data_dir()
     user_dir = dd / user.handle
     for index_path in (user_dir / "_merged" / "index.json", user_dir / "index.json"):
-        if index_path.exists():
+        if not index_path.exists():
-            index = json.loads(index_path.read_text())
+            continue
-            return JSONResponse({"activities": index.get("activities", [])})
+        index = json.loads(index_path.read_text())
+        activities: list[dict] = index.get("activities", [])
+        for shard in index.get("shards", []):
+            shard_path = index_path.parent / shard["url"]
+            if shard_path.exists():
+                shard_doc = json.loads(shard_path.read_text())
+                activities.extend(shard_doc.get("activities", []))
+        return JSONResponse({"activities": activities})
     return JSONResponse({"activities": []})
 
 

mobile/app/(tabs)/index.tsx

@@ -18,10 +18,12 @@ export default function FeedScreen() {
     setSyncing(false);
     if (result.error) {
       setSyncMsg(result.error);
+    } else if (result.total === 0) {
+      setSyncMsg('No activities on instance');
     } else if (result.synced === 0) {
-      setSyncMsg('Already up to date');
+      setSyncMsg(`Up to date (${result.total} activities)`);
     } else {
-      setSyncMsg(`${result.synced} ${result.synced === 1 ? 'activity' : 'activities'} synced`);
+      setSyncMsg(`${result.synced} of ${result.total} activities synced`);
     }
     setTimeout(() => setSyncMsg(null), 3500);
   }, [db]);

mobile/db/sync.ts

@@ -1,14 +1,14 @@
 import type { SQLiteDatabase } from 'expo-sqlite';
 import { getSetting, upsertRemoteActivity } from './queries';
 
-export type SyncResult = { synced: number; error?: string };
+export type SyncResult = { synced: number; total: number; error?: string };
 
 export async function syncFeed(db: SQLiteDatabase): Promise<SyncResult> {
   const instanceUrl = (await getSetting(db, 'instance_url'))?.replace(/\/$/, '');
   const token = await getSetting(db, 'api_token');
 
   if (!instanceUrl || !token) {
-    return { synced: 0, error: 'No instance configured — add one in Settings.' };
+    return { synced: 0, total: 0, error: 'No instance configured — add one in Settings.' };
   }
 
   let resp: Response;
@@ -17,14 +17,14 @@ export async function syncFeed(db: SQLiteDatabase): Promise<SyncResult> {
       headers: { Authorization: `Bearer ${token}` },
     });
   } catch {
-    return { synced: 0, error: 'Could not reach instance — check your connection.' };
+    return { synced: 0, total: 0, error: 'Could not reach instance — check your connection.' };
   }
 
   if (resp.status === 401) {
-    return { synced: 0, error: 'Session expired — reconnect in Settings.' };
+    return { synced: 0, total: 0, error: 'Session expired — reconnect in Settings.' };
   }
   if (!resp.ok) {
-    return { synced: 0, error: `Server error (${resp.status})` };
+    return { synced: 0, total: 0, error: `Server error (${resp.status})` };
   }
 
   const data: { activities?: RemoteSummary[] } = await resp.json();
@@ -48,7 +48,7 @@ export async function syncFeed(db: SQLiteDatabase): Promise<SyncResult> {
     if (changed) synced++;
   }
 
-  return { synced };
+  return { synced, total: activities.length };
 }
 
 type RemoteSummary = {