refactor(material-temporal-adapter): use native Temporal types

- Replace custom TemporalDateType interface with union type of native
  Temporal.PlainDate | Temporal.PlainDateTime | Temporal.ZonedDateTime
- Update temporal.d.ts to match TC39 spec and TypeScript PR #62628
  (microsoft/TypeScript#62628)
- Types match MDN documentation and Chrome 144/Firefox 139 implementations
- Add _invalid marker to sentinel object for explicit invalid detection
- Adapter uses global Temporal namespace without polyfill dependency
- Polyfill (@js-temporal/polyfill) is only used in tests

Author: kbrilla

src/material-temporal-adapter/adapter/temporal-date-adapter.ts

@@ -33,77 +33,13 @@ export type TemporalCalendarId = string;
 
 /**
  * Represents a date in the Temporal API format.
- * This interface is compatible with `Temporal.PlainDate`, `Temporal.PlainDateTime`,
- * and `Temporal.ZonedDateTime`.
- *
- * The interface provides read-only access to date components and includes methods
- * for date manipulation. When used with the TemporalDateAdapter, instances will be
- * actual `Temporal.PlainDate`, `Temporal.PlainDateTime`, or `Temporal.ZonedDateTime` objects.
+ * Can be a PlainDate, PlainDateTime, or ZonedDateTime depending on the adapter mode.
  *
  * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDate
  * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/PlainDateTime
  * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/ZonedDateTime
  */
-export interface TemporalDateType {
-  /** The year component (may be negative for BCE dates). */
-  readonly year: number;
-  /** The month component (1-12). */
-  readonly month: number;
-  /** The day of month component (1-31). */
-  readonly day: number;
-  /**
-   * The calendar system identifier used by this date.
-   * This is the standard property in the current Temporal spec.
-   */
-  readonly calendarId?: string;
-  /** The day of the week (1-7, where 1 is Monday). */
-  readonly dayOfWeek: number;
-  /** The number of days in the month. */
-  readonly daysInMonth: number;
-  /** The number of months in the year. */
-  readonly monthsInYear: number;
-
-  // Optional time components (present in PlainDateTime and ZonedDateTime)
-  /** The hour component (0-23). Only present in PlainDateTime/ZonedDateTime. */
-  readonly hour?: number;
-  /** The minute component (0-59). Only present in PlainDateTime/ZonedDateTime. */
-  readonly minute?: number;
-  /** The second component (0-59). Only present in PlainDateTime/ZonedDateTime. */
-  readonly second?: number;
-  /** The millisecond component (0-999). Only present in PlainDateTime/ZonedDateTime. */
-  readonly millisecond?: number;
-
-  // Optional timezone components (present in ZonedDateTime)
-  /** The timezone identifier. Only present in ZonedDateTime. */
-  readonly timeZoneId?: string;
-
-  /**
-   * Returns a new date with the specified duration added.
-   * @param duration The duration to add (e.g., `{years: 1}`, `{months: 2}`, `{days: 7}`).
-   */
-  add(duration: {years?: number; months?: number; days?: number}): TemporalDateType;
-
-  /**
-   * Returns a new PlainDateTime from this date with the specified time.
-   * @param time The time components to use.
-   */
-  toPlainDateTime?(time: {
-    hour?: number;
-    minute?: number;
-    second?: number;
-    millisecond?: number;
-  }): TemporalDateType;
-
-  /**
-   * Returns a string representation of this date.
-   */
-  toString(): string;
-
-  /**
-   * Returns true if this date equals the other date.
-   */
-  equals(other: TemporalDateType): boolean;
-}
+export type TemporalDateType = Temporal.PlainDate | Temporal.PlainDateTime | Temporal.ZonedDateTime;
 
 /**
  * Mode for the Temporal adapter - determines which type is used internally.
@@ -405,12 +341,13 @@ export class TemporalDateAdapter extends DateAdapter<TemporalDateType> {
   /** Clones the given date. */
   clone(date: TemporalDateType): TemporalDateType {
     if (this._isZonedDateTime(date)) {
-      return Temporal.ZonedDateTime.from(this._toZonedDateTime(date));
+      // Use toString() to clone - from() accepts string
+      return Temporal.ZonedDateTime.from(date.toString());
     }
     if (this._isPlainDateTime(date)) {
-      return Temporal.PlainDateTime.from(this._toPlainDateTime(date));
+      return Temporal.PlainDateTime.from(date.toString());
     }
-    return Temporal.PlainDate.from(this._toPlainDate(date));
+    return Temporal.PlainDate.from(date.toString());
   }
 
   /**
@@ -728,7 +665,10 @@ export class TemporalDateAdapter extends DateAdapter<TemporalDateType> {
   /** Checks whether the given date is valid. */
   isValid(date: TemporalDateType): boolean {
     // Temporal doesn't create invalid dates - it throws instead.
-    // Our invalid() returns a sentinel object with NaN values.
+    // Our invalid() returns a sentinel object with NaN values and _invalid marker.
+    if ((date as {_invalid?: boolean})._invalid === true) {
+      return false;
+    }
     return date != null && typeof date.year === 'number' && !isNaN(date.year);
   }
 
@@ -744,8 +684,9 @@ export class TemporalDateAdapter extends DateAdapter<TemporalDateType> {
    */
   invalid(): TemporalDateType {
     // Temporal doesn't support invalid dates like Date(NaN).
-    // Return minimal sentinel with NaN year - isValid() checks this.
+    // Return sentinel with _invalid marker and NaN values.
     const baseInvalid = {
+      _invalid: true as const,
       year: NaN,
       month: NaN,
       day: NaN,
@@ -1090,15 +1031,15 @@ export class TemporalDateAdapter extends DateAdapter<TemporalDateType> {
     if (this._isZonedDateTime(date)) {
       return this._toZonedDateTime(date).toPlainDateTime();
     }
-    return date as Temporal.PlainDateTime;
+    return date as unknown as Temporal.PlainDateTime;
   }
 
   /**
    * Converts a TemporalDateType to Temporal.ZonedDateTime for internal use.
    * This is needed because our public interface doesn't expose Temporal types directly.
    */
   private _toZonedDateTime(date: TemporalDateType): Temporal.ZonedDateTime {
-    return date as Temporal.ZonedDateTime;
+    return date as unknown as Temporal.ZonedDateTime;
   }
 
   /**