Enhance filter modal: prevent stacking and improve tab navigation

tests/test_app.py

@@ -72,6 +72,51 @@ async def test_filter_shortcut_opens_modal_and_applies_the_selected_filter():
     ]
 
 
+@pytest.mark.asyncio
+async def test_filter_shortcut_does_not_stack_filter_modals():
+    """Repeated filter shortcuts keep the existing filter modal in focus."""
+    app = app_with_filterable_entries()
+
+    async with app.run_test() as pilot:
+        await pilot.press("ctrl+f")
+        await pilot.pause()
+
+        await pilot.press("ctrl+f")
+        await pilot.press("ctrl+f")
+        await pilot.pause()
+
+        assert isinstance(app.screen, FilterModal)
+        assert sum(isinstance(screen, FilterModal) for screen in app.screen_stack) == 1
+
+
+@pytest.mark.asyncio
+async def test_filter_modal_tabs_through_controls_in_visual_order():
+    """The modal starts at Presets and tabs through the visible controls in order."""
+    app = app_with_filterable_entries()
+
+    async with app.run_test() as pilot:
+        await pilot.press("ctrl+f")
+        await pilot.pause()
+
+        assert app.focused is app.screen.query_one("#preset-select")
+        for expected_id in (
+            "load-preset",
+            "save-preset",
+            "delete-preset",
+            "status-filter-type",
+            "type-filter-type",
+            "resolution-filter-type",
+            "search-term",
+            "search-hostnames",
+            "search-comments",
+            "search-ips",
+            "search-case-sensitive",
+            "apply",
+        ):
+            await pilot.press("tab")
+            assert app.focused is app.screen.query_one(f"#{expected_id}")
+
+
 @pytest.mark.asyncio
 async def test_filter_reset_clears_filters_and_cancel_preserves_applied_filters():
     """Reset clears the form on Apply, while Cancel leaves the applied filter alone."""