exif(): read HEIF/HEIC originals with exifreader (closes #145)

`photo.exif()` and `quak backup-metadata --exif` now read EXIF through `exifreader`. HEIC/HEIF originals get EXIF, including a live photo's image, as do the other formats `exifreader` reads. It replaces `exif-reader` and the hand-written JPEG scan. `PhotoExif` is unchanged.

The `backup-metadata` dump now holds `exifreader`'s tag output, with unnamed tags keyed `undefined-` plus their number. GPS altitude without a reference counts as above sea level. A latitude or longitude without its hemisphere tag, an unreadable text tag, and a date the parser rejects each give no field.

Licence: `exifreader` is MPL-2.0, used unmodified.

Model: opus-5-5

test/library/content-library.test.ts

@@ -25,7 +25,16 @@ import { Library, type LibraryOptions } from "../../src/library/index.js";
 import type { ContentSource } from "../../src/library/content.js";
 import type { CollectionsPage, FilesPage } from "../../src/client.js";
 import type { Collection, EnteFile } from "../../src/model/types.js";
-import { asLivePhoto, cdnSource, IMAGE, livePhotoZip } from "../live-photo.js";
+import type { PhotoExif } from "../../src/exif.js";
+import { HEIC_WITH_EXIF } from "../exif-heic.js";
+import {
+    asLivePhoto,
+    cdnSource,
+    IMAGE,
+    livePhotoHash,
+    livePhotoZip,
+    VIDEO,
+} from "../live-photo.js";
 
 const USER_ID = 7;
 
@@ -297,7 +306,7 @@ const JPEG_WITH_EXIF = new Uint8Array([
 ]);
 
 // A JPEG whose EXIF segment is laid out correctly but holds "XX" where the TIFF
-// byte order belongs, so exif-reader cannot parse it.
+// byte order belongs, so exifreader cannot parse it.
 const JPEG_WITH_BAD_EXIF = new Uint8Array([
     ...[0xff, 0xd8], // start of image
     ...[0xff, 0xe1, ...u16(2 + 6 + 2)], // APP1 and its length
@@ -411,7 +420,49 @@ describe("Photo save path, local copy, content and EXIF", () => {
         await lib.close();
     });
 
-    it("returns no EXIF fields for an original that is not a JPEG", async () => {
+    // What exif() returns for HEIC_WITH_EXIF, which holds the same values as
+    // JPEG_WITH_EXIF.
+    const heicFields: PhotoExif = {
+        make: "Canon",
+        model: "EOS R5",
+        lensModel: "RF50mm F1.8 STM",
+        dateTimeOriginal: new Date(Date.UTC(2021, 6, 15, 14, 30)),
+        offsetTimeOriginal: "+02:00",
+        exposureTime: 1 / 250,
+        fNumber: 2.8,
+        iso: 400,
+        focalLength: 50,
+        orientation: 6,
+        gpsLatitude: 40 + 26 / 60 + 46 / 3600,
+        gpsLongitude: -(79 + 58 / 60 + 56 / 3600),
+        gpsAltitude: -12.5,
+    };
+
+    it("reads the same common EXIF fields from a HEIC original", async () => {
+        const lib = await open({ contentSource: stubSource(HEIC_WITH_EXIF) });
+        expect(await lib.photos.byID({ fileID: 1 })!.exif()).toStrictEqual(
+            heicFields,
+        );
+        await lib.close();
+    });
+
+    it("reads the EXIF of a live photo whose image is a HEIC", async () => {
+        const { file: live, body } = await asLivePhoto(
+            file(1, 1),
+            livePhotoZip({ "image.heic": HEIC_WITH_EXIF, "video.mov": VIDEO }),
+            livePhotoHash(HEIC_WITH_EXIF, VIDEO),
+        );
+        const lib = await open({
+            client: new FilesClient([live]),
+            contentSource: cdnSource(new Map([[1, body]])),
+        });
+        expect(await lib.photos.byID({ fileID: 1 })!.exif()).toStrictEqual(
+            heicFields,
+        );
+        await lib.close();
+    });
+
+    it("returns no EXIF fields for an original that is not an image", async () => {
         const lib = await open();
         expect(await lib.photos.byID({ fileID: 1 })!.exif()).toStrictEqual({});
         await lib.close();