feat(tui): unify keyboard and mouse navigation

Declare every dashboard key as a Binding on the widget that owns it, and
generate the footer, activity tool chips and help screen from those
bindings so they cannot drift. The footer collapses to "? help · q quit"
under 80x24.

Add Home/End and PgUp/PgDn (one week) navigation, mouse-wheel selection on
the graphs, click-to-focus on every panel, and clickable footer chips.
Tab and Shift+Tab now visit only the dashboard panels.

tests/test_tui.py

@@ -1357,15 +1357,9 @@ class TestConstrainedLayout:
             headline = str(app.query_one("#headline-band").render())
             assert "remaining" in headline.lower() or "projection" in headline.lower()
 
-            # Service strip should have actions
-            strip = str(app.query_one("#action-rail").render())
-            assert "p Pause" in strip
-            assert "r Resume" in strip
-            assert "q Quit TUI" in strip
-
-            # Quit rail should be visible
+            # Under 80x24 the footer collapses to help and quit (issue #110)
             rail = str(app.query_one("#action-rail").render())
-            assert "Quit" in rail
+            assert rail == "? help · q quit"
 
     @pytest.mark.asyncio
     async def test_constrained_long_reasons_visible(self, tmp_path):