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.

README.md

@@ -271,16 +271,20 @@ shows incomplete or unavailable dates without treating them as zero. Older
 UTC-only summaries cannot establish exact local-day totals.
 
 - `v` cycles Live / Day / History; the tabs are also clickable.
-- `←` / `→` inspect points; `w` switches read/write volume in every view.
+- `←` / `→` inspect points, `Home` / `End` jump to the first or last point, and
+  `PgUp` / `PgDn` jump a week in Day and History (the live window is three
+  hours); the mouse wheel moves the selection too. `w`
+  switches read/write volume in every view.
 - `[` / `]` browse dates, `g` enters a date, and `t` returns to today/live.
-- `Tab` / `Shift+Tab` move focus; `z` expands the focused panel, and `z` or
-  `Esc` restores it. Monitoring status and controls remain visible.
+- `Tab` / `Shift+Tab` move focus between panels (clicking a panel focuses it);
+  `z` expands the focused panel, and `z` or `Esc` restores it. Monitoring status and controls remain visible.
 - `s` cycles Chalktone, Amber, Nord, and High Contrast; saved theme preferences
   survive upgrades. `m` toggles reduced motion.
 
 On smaller terminals, textual summaries and scrollable panels keep evidence
 accessible. Pause, resume, collect, disclosures, help, and quit remain available
-in the fixed control row.
+in the fixed control row, which collapses to `? help · q quit` under 80×24. `?`
+lists every key; the footer and help are generated from the same bindings.
 
 Run `fenris` as your normal user to open the TUI dashboard. The dashboard does
 not need `sudo`. Use `sudo` for package installation and system configuration;