chore: add initial DAO/DTO interfaces

Prep for Firebase v10/AngularFire v16
migration

Author: EdricChan03

src/app/data/converters/non-primitive-utils.ts

@@ -0,0 +1,17 @@
+import { FieldValue, Timestamp, WithFieldValue } from '@firebase/firestore';
+import { toTimestamp } from '@app/data/models/dto/temporal';
+import { Temporal } from 'temporal-polyfill';
+
+export const setToDto = <T>(set: FieldValue | WithFieldValue<Set<T>>): FieldValue | T[] => {
+  if (set instanceof FieldValue) return set;
+  if (set instanceof Set) return [...set];
+
+  throw new Error('WithFieldValue of a Set is not supported');
+};
+
+export const temporalInstantToDto = (instant: FieldValue | WithFieldValue<Temporal.Instant>): FieldValue | Timestamp => {
+  if (instant instanceof FieldValue) return instant;
+  if (instant instanceof Temporal.Instant) return toTimestamp(instant);
+
+  throw new Error('WithFieldValue of a Temporal.Instant is not supported');
+}

src/app/data/models/dao/metadata.ts

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+import { Temporal } from 'temporal-polyfill';
+
+export { HasId } from '../common/id';
+
+export interface WithTimestampMetadata {
+  /** Date when this document was last modified at. */
+  lastModified: Temporal.Instant;
+  /** Date when this document was created. */
+  createdAt: Temporal.Instant;
+}
+
+export interface WithTimestampMetadataJson {
+  /** Date when this document was last modified at, in ISO8601 form. */
+  lastModified: string;
+  /** Date when this document was created, in ISO8601 form. */
+  createdAt: string;
+}

src/app/data/models/dao/parsers.ts

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+import { Temporal } from 'temporal-polyfill';
+import { Timestamp } from '@firebase/firestore';
+
+export const toBoolean = (value: unknown): boolean => {
+  if (typeof value === 'boolean') return value;
+  if (typeof value === 'string') return value === 'true';
+  return Boolean(value);
+}
+
+export const toInstantOrNull = (value: unknown): Temporal.Instant | null => {
+  if (value instanceof Temporal.Instant) return value;
+  if (value instanceof Timestamp) return Temporal.Instant.fromEpochMilliseconds(value.toMillis());
+  if (typeof value === 'string') return Temporal.Instant.from(value);
+  if (typeof value === 'number') return Temporal.Instant.fromEpochMilliseconds(value);
+  return null;
+}

src/app/data/models/dto/temporal.ts

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+import { Temporal } from 'temporal-polyfill';
+import { Timestamp } from '@firebase/firestore';
+
+/** Converts the specified `instant` to its Firestore {@link Timestamp} equivalent. */
+export const toTimestamp = (instant: Temporal.Instant): Timestamp => Timestamp.fromMillis(instant.epochMilliseconds);