Remove the content cache's handling of an earlier version's live-photo ZIP (closes #151)

quak is pre-1.0 and keeps no handling of old data. The content cache no longer recognises or removes a live photo that an earlier quak version cached as one ZIP. A live-photo download no longer removes what was at its destination before renaming the image and video into place; the rename already replaces it. The README sentences and the tests about that old ZIP are gone. The two removed tests that also covered current behaviour are replaced by tests with no ZIP: the cache re-fetching a live photo recorded with no video, and the library telling the cache which files are live photos when it opens.

Model: opus-5-5

test/library/content-library.test.ts

@@ -176,7 +176,7 @@ describe("Library content wiring", () => {
         await lib.close();
     });
 
-    it("removes a live photo's ZIP an earlier version cached when it opens, and precaches its image and video", async () => {
+    it("does not take a live photo's image or video with no JSON file as its original when it opens, and precaches both", async () => {
         const { file: live, body } = await asLivePhoto(file(1, 1));
         class LiveClient extends MockClient {
             override async filesSince(): Promise<FilesPage> {
@@ -197,7 +197,8 @@ describe("Library content wiring", () => {
         // A first run records the library, so the next one knows that file 1
         // is a live photo when it opens the cache.
         await (await open({})).close();
-        writeFileSync(join(originals, "1.jpg"), livePhotoZip());
+        writeFileSync(join(originals, "1.heic"), "an image");
+        writeFileSync(join(originals, "1.mov"), "a video");
 
         let precached!: () => void;
         const done = new Promise<void>((r) => (precached = r));
@@ -208,7 +209,9 @@ describe("Library content wiring", () => {
                     precached();
             },
         });
-        expect(existsSync(join(originals, "1.jpg"))).toBe(false);
+        expect(
+            lib.photos.byID({ fileID: 1 })!.record().originalPath,
+        ).toBeUndefined();
         await done;
 
         expect(readdirSync(originals).sort()).toEqual([
@@ -216,6 +219,17 @@ describe("Library content wiring", () => {
             "1.livephoto.json",
             "1.mov",
         ]);
+        expect(readFileSync(join(originals, "1.heic"))).toEqual(
+            Buffer.from(IMAGE),
+        );
+        expect(readFileSync(join(originals, "1.mov"))).toEqual(
+            Buffer.from(VIDEO),
+        );
+        expect(
+            JSON.parse(
+                readFileSync(join(originals, "1.livephoto.json"), "utf-8"),
+            ),
+        ).toEqual({ image: "1.heic", video: "1.mov" });
         expect(lib.photos.byID({ fileID: 1 })!.record().originalPath).toBe(
             join(originals, "1.heic"),
         );