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/cli/commands.test.ts

@@ -56,6 +56,7 @@ import type { ContentSource } from "../../src/library/content.js";
 import type { Collection, EnteFile } from "../../src/model/types.js";
 import { init, toBase64 } from "../../src/crypto/index.js";
 import { defaultCacheDirectory } from "../../src/library/index.js";
+import { HEIC_WITH_EXIF } from "../exif-heic.js";
 import {
     asLivePhoto,
     cdnSource,
@@ -653,6 +654,31 @@ describe("a live photo", () => {
             height: 4,
         });
     });
+
+    it("backup-metadata --exif records the EXIF of a HEIC image", async () => {
+        const dir = join(root, "dump");
+
+        expect(
+            await backupMetadataCommand(
+                context(await livePhotoClient(HEIC_WITH_EXIF)),
+                dir,
+                { exif: true },
+            ),
+        ).toBe(0);
+
+        const record = JSON.parse(
+            readFileSync(
+                join(dir, "collections", "1-Vacation", "300.json"),
+                "utf-8",
+            ),
+        );
+        expect(record.imageMetadata.exifError).toBeUndefined();
+        expect(record.imageMetadata.exif).toMatchObject({
+            Make: { value: ["Canon"] },
+            Model: { value: ["EOS R5"] },
+            DateTimeOriginal: { value: ["2021:07:15 14:30:00"] },
+        });
+    });
 });
 
 describe("backup", () => {