wealthfolio: add compute_position_qty for broker reconciliation

tests/sinks/test_wealthfolio.py

@@ -373,3 +373,62 @@ async def test_push_manual_snapshots_short_circuits_on_empty(
     sink = _client(httpx.MockTransport(handler), sp)
     result = await sink.push_manual_snapshots(account_id="acct", snapshots=[])
     assert result["snapshotsImported"] == 0
+
+
+# -- compute_position_qty (used by IBKR reconciliation) --
+
+
+@pytest.mark.asyncio
+async def test_compute_position_qty_sums_buys_minus_sells(tmp_path: Path) -> None:
+    """Sums BUY/ADD_HOLDING/TRANSFER_IN minus SELL/REMOVE_HOLDING/TRANSFER_OUT
+    quantities per symbol, skipping cash activities."""
+    sp = tmp_path / "s.json"
+    sp.write_text(json.dumps({"cookies": {"wf_token": "fresh"}}))
+
+    page_1: dict[str, Any] = {
+        "activities": [
+            {"symbol": "VUAG.L", "activityType": "BUY", "quantity": "10"},
+            {"symbol": "VUAG.L", "activityType": "SELL", "quantity": "2"},
+            {"symbol": "AAPL", "activityType": "BUY", "quantity": "5"},
+            {"symbol": "$CASH-GBP", "activityType": "DEPOSIT", "quantity": "0",
+             "amount": "100"},
+            # Unknown activity type — must be skipped, not crash.
+            {"symbol": "VUAG.L", "activityType": "DIVIDEND", "quantity": "0",
+             "amount": "0.5"},
+        ],
+        "totalPages": 1,
+    }
+
+    async def handler(req: httpx.Request) -> httpx.Response:
+        if req.url.path == "/api/v1/activities/search":
+            return httpx.Response(200, json=page_1)
+        raise AssertionError(f"unexpected request: {req.method} {req.url.path}")
+
+    sink = _client(httpx.MockTransport(handler), sp)
+    result = await sink.compute_position_qty("acct-123")
+    assert result == {"VUAG.L": Decimal("8"), "AAPL": Decimal("5")}
+
+
+@pytest.mark.asyncio
+async def test_compute_position_qty_paginates(tmp_path: Path) -> None:
+    """Walks all pages until totalPages reached."""
+    sp = tmp_path / "s.json"
+    sp.write_text(json.dumps({"cookies": {"wf_token": "fresh"}}))
+
+    pages: dict[int, dict[str, Any]] = {
+        1: {"activities": [{"symbol": "VUAG.L", "activityType": "BUY",
+                             "quantity": "3"}], "totalPages": 2},
+        2: {"activities": [{"symbol": "VUAG.L", "activityType": "BUY",
+                             "quantity": "4"}], "totalPages": 2},
+    }
+    seen_pages: list[int] = []
+
+    async def handler(req: httpx.Request) -> httpx.Response:
+        body = json.loads(req.content)
+        seen_pages.append(body["page"])
+        return httpx.Response(200, json=pages[body["page"]])
+
+    sink = _client(httpx.MockTransport(handler), sp)
+    result = await sink.compute_position_qty("acct-x")
+    assert sorted(seen_pages) == [1, 2]
+    assert result == {"VUAG.L": Decimal("7")}