Cover notifier.py error paths (TEST_MODE, HTTP error, connection error)

Brings app/notifier.py from 73% to 100% test coverage by exercising the
three notification functions' TEST_MODE early-return, non-204 response,
and requests exception branches — the exact paths a requests upgrade
regression would break silently.

tests/test_notifier.py

@@ -52,6 +52,50 @@ def test_in_stock_notification_posts_expected_payload(monkeypatch):
     assert "RTX 5090 Founders Edition" in embed["title"]
 
 
+def test_discord_notification_survives_http_error(monkeypatch):
+    notifier = _import_notifier(monkeypatch, test_mode="False")
+    monkeypatch.setattr(notifier.requests, "post", lambda *a, **k: FakeResponse(status_code=500, text="boom"))
+
+    notifier.send_discord_notification("RTX 5090 Founders Edition", "https://example.com", "1999")
+
+
+def test_discord_notification_survives_connection_error(monkeypatch):
+    notifier = _import_notifier(monkeypatch, test_mode="False")
+
+    def raise_error(*a, **k):
+        raise notifier.requests.exceptions.ConnectionError("boom")
+
+    monkeypatch.setattr(notifier.requests, "post", raise_error)
+
+    # Should not raise even though the request itself blew up (network down, DNS, etc.)
+    notifier.send_discord_notification("RTX 5090 Founders Edition", "https://example.com", "1999")
+
+
+def test_out_of_stock_test_mode_skips_network_call(monkeypatch):
+    notifier = _import_notifier(monkeypatch, test_mode="True")
+    calls = []
+    monkeypatch.setattr(notifier.requests, "post", lambda *a, **k: calls.append((a, k)))
+
+    notifier.send_out_of_stock_notification("RTX 5090 Founders Edition", "https://example.com", "1999")
+
+    assert calls == []
+
+
+def test_out_of_stock_notification_posts_on_success(monkeypatch):
+    notifier = _import_notifier(monkeypatch, test_mode="False")
+    captured = {}
+
+    def fake_post(url, json=None, **kwargs):
+        captured["json"] = json
+        return FakeResponse(status_code=204)
+
+    monkeypatch.setattr(notifier.requests, "post", fake_post)
+
+    notifier.send_out_of_stock_notification("RTX 5090 Founders Edition", "https://example.com/buy", "1999")
+
+    assert captured["json"]["embeds"][0]["url"] == "https://example.com/buy"
+
+
 def test_out_of_stock_notification_survives_http_error(monkeypatch):
     notifier = _import_notifier(monkeypatch, test_mode="False")
     monkeypatch.setattr(notifier.requests, "post", lambda *a, **k: FakeResponse(status_code=500, text="boom"))
@@ -60,6 +104,45 @@ def test_out_of_stock_notification_survives_http_error(monkeypatch):
     notifier.send_out_of_stock_notification("RTX 5090 Founders Edition", "https://example.com", "1999")
 
 
+def test_out_of_stock_notification_survives_connection_error(monkeypatch):
+    notifier = _import_notifier(monkeypatch, test_mode="False")
+
+    def raise_error(*a, **k):
+        raise notifier.requests.exceptions.ConnectionError("boom")
+
+    monkeypatch.setattr(notifier.requests, "post", raise_error)
+
+    notifier.send_out_of_stock_notification("RTX 5090 Founders Edition", "https://example.com", "1999")
+
+
+def test_sku_change_test_mode_skips_network_call(monkeypatch):
+    notifier = _import_notifier(monkeypatch, test_mode="True")
+    calls = []
+    monkeypatch.setattr(notifier.requests, "post", lambda *a, **k: calls.append((a, k)))
+
+    notifier.send_sku_change_notification("RTX 5090 Founders Edition", "old-sku", "new-sku", "https://example.com")
+
+    assert calls == []
+
+
+def test_sku_change_notification_survives_http_error(monkeypatch):
+    notifier = _import_notifier(monkeypatch, test_mode="False")
+    monkeypatch.setattr(notifier.requests, "post", lambda *a, **k: FakeResponse(status_code=500, text="boom"))
+
+    notifier.send_sku_change_notification("RTX 5090 Founders Edition", "old-sku", "new-sku", "https://example.com")
+
+
+def test_sku_change_notification_survives_connection_error(monkeypatch):
+    notifier = _import_notifier(monkeypatch, test_mode="False")
+
+    def raise_error(*a, **k):
+        raise notifier.requests.exceptions.ConnectionError("boom")
+
+    monkeypatch.setattr(notifier.requests, "post", raise_error)
+
+    notifier.send_sku_change_notification("RTX 5090 Founders Edition", "old-sku", "new-sku", "https://example.com")
+
+
 def test_sku_change_notification_mentions_role_and_skus(monkeypatch):
     notifier = _import_notifier(monkeypatch, test_mode="False", discord_roles="<@&123456789012345678>")
     captured = {}