fix(web): drop the provider label from the plan-usage chip when there is only one

The chip prefixes every row with the provider name, so a machine that only
has Claude limits renders "CLAUDE 5H 60% 7D 23%" — a 46px label naming the
only thing it could possibly be. The name exists to tell two rows apart, so
it should only appear when there are two.

updatePlanUsageChip() now checks whether both Claude and Codex actually have
windows before building the rows, and emits the .pu-provider span only in
that case. The tooltip keeps naming the provider in both cases: it has the
room, and the chip no longer does.

Verified in a browser on an isolated beta instance: Claude-only renders bare
windows with no .pu-provider in the DOM, Codex-only the same, and the
two-provider chip is byte-identical to before.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

test/plan-usage-chip.test.ts

@@ -79,4 +79,36 @@ describe('header plan usage chip', () => {
     expect(codexRow).not.toContain('5h');
     expect(codexRow).toContain('7d');
   });
+
+  it('drops the provider label when Claude is the only provider with limits', () => {
+    const { CodemanApp, chip } = loadCodemanAppClass();
+    const app = Object.create((CodemanApp as { prototype: object }).prototype) as UsageApp;
+
+    app.updatePlanUsageChip({
+      fiveHour: { usedPercentage: 60, resetAt: 1000 },
+      sevenDay: { usedPercentage: 23, resetAt: 2000 },
+    });
+
+    expect(chip.innerHTML).toContain('class="pu-row"');
+    expect(chip.innerHTML).not.toContain('pu-provider');
+    expect(chip.innerHTML).not.toContain('Claude');
+    expect(chip.innerHTML).toContain('60%');
+    expect(chip.innerHTML).toContain('23%');
+    // The tooltip still names the provider — it has room, and the chip no longer does.
+    expect(chip.title).toContain('Claude plan usage');
+  });
+
+  it('drops the provider label when Codex is the only provider with limits', () => {
+    const { CodemanApp, chip } = loadCodemanAppClass();
+    const app = Object.create((CodemanApp as { prototype: object }).prototype) as UsageApp;
+
+    app.updatePlanUsageChip({
+      codex: { fiveHour: { usedPercentage: 12, resetAt: 3000 } },
+    });
+
+    expect(chip.innerHTML).toContain('class="pu-row"');
+    expect(chip.innerHTML).not.toContain('pu-provider');
+    expect(chip.innerHTML).toContain('12%');
+    expect(chip.title).toContain('Codex plan usage');
+  });
 });