fix(mobile/upload): activities now appear in browser after upload; reconcile synced_at on fresh server

Three bugs fixed:
- /api/upload/bas and /api/upload/raw never updated user_dir/index.json, so
  merge_all couldn't include uploaded activities in year shards — they existed
  on disk but were invisible to the browser feed. Fixed by _upsert_index_summary()
  called before merge_all().
- Silent catch {} in uploadLocalActivities swallowed all per-activity errors;
  replaced with console.warn so failures are visible in Expo logs.
- After a server wipe, synced_at flags on the device caused "Nothing to upload"
  forever. uploadFeed() now reconciles against GET /api/feed at the start of each
  upload: local activities not found on the server get synced_at cleared.

Also: live upload progress ("Uploading N / M…"), failed count in result message,
onProgress callback on uploadFeed(), countPendingUploads() helper.

bincio/serve/server.py

@@ -487,6 +487,67 @@ async def get_activity_timeseries(
     raise HTTPException(404, "Timeseries not found")
 
 
+def _upsert_index_summary(user_dir: Path, activity_id: str, activity: dict, geojson: Optional[dict] = None) -> None:
+    """Add or update an activity summary in user_dir/index.json.
+
+    Called after writing BAS activity files so that merge_all can include the
+    activity in year shards.  Without this, uploaded activities exist on disk
+    but never appear in the browser feed.
+    """
+    # Build preview coords from geojson if available ([lat, lng] order)
+    preview: Optional[list] = None
+    if geojson:
+        try:
+            coords = geojson.get("geometry", {}).get("coordinates", [])
+            if coords:
+                step = max(1, len(coords) // 9)
+                preview = [[c[1], c[0]] for c in coords[::step]][:9]
+        except Exception:
+            pass
+
+    has_track = (user_dir / "activities" / f"{activity_id}.geojson").exists()
+    summary = {
+        "id": activity_id,
+        "title": activity.get("title", activity_id),
+        "sport": activity.get("sport"),
+        "sub_sport": activity.get("sub_sport"),
+        "started_at": activity.get("started_at"),
+        "distance_m": activity.get("distance_m"),
+        "duration_s": activity.get("duration_s"),
+        "moving_time_s": activity.get("moving_time_s"),
+        "elevation_gain_m": activity.get("elevation_gain_m"),
+        "avg_speed_kmh": activity.get("avg_speed_kmh"),
+        "max_speed_kmh": activity.get("max_speed_kmh"),
+        "avg_hr_bpm": activity.get("avg_hr_bpm"),
+        "max_hr_bpm": activity.get("max_hr_bpm"),
+        "avg_cadence_rpm": activity.get("avg_cadence_rpm"),
+        "avg_power_w": activity.get("avg_power_w"),
+        "mmp": activity.get("mmp"),
+        "best_efforts": activity.get("best_efforts"),
+        "best_climb_m": activity.get("best_climb_m"),
+        "source": activity.get("source"),
+        "privacy": activity.get("privacy", "public"),
+        "detail_url": f"activities/{activity_id}.json",
+        "track_url": f"activities/{activity_id}.geojson" if has_track else None,
+        "preview_coords": preview,
+    }
+
+    index_path = user_dir / "index.json"
+    if index_path.exists():
+        index_data = json.loads(index_path.read_text(encoding="utf-8"))
+    else:
+        index_data = {
+            "bas_version": "1.0",
+            "owner": {"handle": user_dir.name},
+            "generated_at": None,
+            "activities": [],
+        }
+    existing = {a["id"]: a for a in index_data.get("activities", [])}
+    existing[activity_id] = summary
+    index_data["activities"] = sorted(existing.values(), key=lambda a: a.get("started_at", ""), reverse=True)
+    index_path.write_text(json.dumps(index_data, indent=2, ensure_ascii=False), encoding="utf-8")
+
+
 @app.post("/api/upload/bas")
 async def upload_bas_activity(
     request: Request,
@@ -527,10 +588,13 @@ async def upload_bas_activity(
         if not ts_path.exists():
             ts_path.write_text(json.dumps(body["timeseries"], ensure_ascii=False), encoding="utf-8")
 
-    if body.get("geojson"):
+    geojson_body: Optional[dict] = body.get("geojson") or None
+    if geojson_body:
         gj_path = acts_dir / f"{activity_id}.geojson"
         if not gj_path.exists():
-            gj_path.write_text(json.dumps(body["geojson"], ensure_ascii=False), encoding="utf-8")
+            gj_path.write_text(json.dumps(geojson_body, ensure_ascii=False), encoding="utf-8")
+
+    _upsert_index_summary(user_dir, activity_id, activity, geojson_body)
 
     from bincio.render.merge import merge_all, write_combined_feed
     merge_all(user_dir)
@@ -622,6 +686,8 @@ async def upload_raw_activity(
         if geojson and not (acts_dir / f"{act_id}.geojson").exists():
             (acts_dir / f"{act_id}.geojson").write_text(json.dumps(geojson), encoding="utf-8")
 
+        _upsert_index_summary(user_dir, act_id, detail, geojson)
+
         from bincio.render.merge import merge_all, write_combined_feed
         merge_all(user_dir)
         write_combined_feed(_get_data_dir())