Refactor HabitColorPicker to use HABIT_COLOR_CHOICES, update styles and tests

- Replaced HABIT_PALETTES with HABIT_COLOR_CHOICES in HabitColorPicker component and related tests.
- Adjusted the layout and styles of the color picker for improved usability.
- Updated tests to reflect changes in color selection logic.
- Modified WorkspacePanel and SettingRow components to allow optional eyebrow and description props.
- Enhanced accessibility tests for calendar navigation.
- Updated calendar model to include a 1-month view option.
- Refined styles across various components for consistency and improved responsiveness.

src/components/design-system/CalendarHeatmap.tsx

@@ -110,13 +110,14 @@ export function CalendarHeatmap({
             year: "numeric",
             timeZone: "UTC",
           })}{" "}
-          –{" "}
+          {months !== 1 && <>–{" "}
           {new Date(`${days.at(-1)!.date}T12:00:00Z`).toLocaleDateString("en", {
             month: "short",
             day: months === "custom" ? "numeric" : undefined,
             year: "numeric",
             timeZone: "UTC",
           })}
+          </>}
         </span>
         <div
           className="ds-month-views"
@@ -127,7 +128,7 @@ export function CalendarHeatmap({
             <button
               key={value}
               type="button"
-              aria-label={`${value} months`}
+              aria-label={`${value} ${value === 1 ? "month" : "months"}`}
               aria-pressed={months === value}
               onClick={() => setMonths(value)}
             >