quak get and get-thumb on an empty cache stop fetching collections once they find the file (closes #222)

`quak get` and `quak get-thumb` used to wait for a refresh, which on an
empty cache fetched the files of every collection. Now, on an empty
cache, `freshFile` reads the collection list, then one collection's
files at a time, and stops at the first that holds the file. That search
stores nothing. Once the cache holds the account's collections,
`freshFile` refreshes as before and looks the file up in the cache. The
commands fetch the content through the new `Library.originalOf()` and
`Library.thumbnailOf()`, which take the file record itself, since the
store may not hold it.

On an empty cache they no longer print a refresh's progress lines. The
`-q` test that relied on `get` refreshing now runs
`helper fix-missing-thumbnails`.

Model: opus-5-5

test/library/content-library.test.ts

@@ -253,6 +253,12 @@ describe("Library content wiring", () => {
         await expect(
             lib.thumbnails.ensure({ fileIDs: [1], priority: "visible" }),
         ).rejects.toThrow(/content cache/i);
+        await expect(lib.originalOf(file(1, 1))).rejects.toThrow(
+            /content cache/i,
+        );
+        await expect(lib.thumbnailOf(file(1, 1))).rejects.toThrow(
+            /content cache/i,
+        );
         await lib.close();
     });
 });