refactor(timeline): move the unstarted-events switch into settings

It shipped as a pill in the board's own header, beside the stacking and
scale controls. That is the wrong company: those two reshape what is
already on the board, which is why they are reached for while reading it,
and this one decides what is on it at all — the same question
"Show events I've finished" and "Show events I'm ignoring" answer, from
the panel where both of those live.

It is the only one of the three scoped to a single view, so the row says
so instead of reading as a promise about the whole app. The board loses
the count the pill carried; with nothing left running it still says how
many are waiting and names the setting, and the page header has said
"N live · N upcoming" all along.

Controls had no tests at all, so the three view filters get some: what
each checkbox is bound to is invisible in a diff and obvious only to the
reader it happens to.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>

test/views.test.tsx

@@ -261,7 +261,6 @@ describe("Timeline stacking", () => {
         group={group}
         onGroup={() => {}}
         showUpcoming={false}
-        onShowUpcoming={() => {}}
         onOpen={() => {}}
         isDone={() => false}
       />,
@@ -316,22 +315,19 @@ describe("Timeline: events that have not started", () => {
         group="ending"
         onGroup={() => {}}
         showUpcoming={showUpcoming}
-        onShowUpcoming={() => {}}
         onOpen={() => {}}
         isDone={() => false}
       />,
     );
 
-  test("the board holds them back by default and says how many", () => {
+  test("the board holds them back by default", () => {
     // Off is the default because the board answers "how does the time I am in
-    // lay out?" — but an absence nobody mentioned is indistinguishable from a
-    // quiet fortnight, which is the wrong thing for this app to imply.
+    // lay out?", and it draws its span from what it plots — so a next patch on
+    // every lane pushes the running bars the reader came for off to the left.
     const html = board(false);
     expect(html).toContain("Closing Ceremony");
     expect(html).not.toContain("Frost Parade");
     expect(html).not.toContain("Long Way Round");
-    expect(html).toContain("Not started");
-    expect(html).toContain(">3<");
   });
 
   test("switching it on plots them", () => {
@@ -340,26 +336,20 @@ describe("Timeline: events that have not started", () => {
     expect(html).toContain("Long Way Round");
   });
 
-  test("the control says which way it is set", () => {
-    expect(board(false)).toContain('aria-pressed="false"');
-    expect(board(true)).toContain('aria-pressed="true"');
-  });
-
-  test("nothing waiting and switched off means no control at all", () => {
-    // A toggle that cannot change anything invites a tap that does nothing.
-    expect(board(false, [row("Closing Ceremony", "genshin", 100)])).not.toContain(
-      "Not started",
-    );
-  });
-
   test("a board with only future events says so rather than reading empty", () => {
     // Otherwise the reader is looking at "nothing to plot" while three events
-    // are scheduled, and the reason is a control they did not notice.
+    // are scheduled, and an absence nobody mentioned is indistinguishable from
+    // a quiet fortnight. It names the setting, since the switch is not on the
+    // board any more.
     const html = board(false, rows.slice(1));
     expect(html).toContain("Nothing is running right now");
     expect(html).toContain("3 events have not started yet");
-    // The control is still there to act on what the sentence just told them.
-    expect(html).toContain("Not started");
+    expect(html).toContain("Show events that haven&#x27;t started");
+  });
+
+  test("one waiting event is counted in words, not as \"1 events\"", () => {
+    const html = board(false, [rows[1]!]);
+    expect(html).toContain("One event has not started yet");
   });
 
   test("each clump of starts is marked in words", () => {