An expired session exits 3 with one line saying to run quak login (closes #164)

A 401 from the server reaches run in src/cli-run.ts as the ApiError the
refresh threw, so run recognises it there, prints one line saying to run
"quak login" and exits 3. A missing or corrupt session file keeps its message
and also exits 3. quak backup meets the 401 on its first refresh, before it
touches any file. Every other error still exits 1.

Judgement call: quak logout is unchanged; it handles its own errors and
deletes the session file whatever the server answers.
Judgement call: quak backup still prints its two progress lines before the
error line.

Model: opus-5-5

README.md

@@ -516,14 +516,17 @@ The CLI stores the snapshot at the platform-appropriate data directory via
 `0600`. The key material is stored in cleartext in the JSON; treat this file as
 you would treat the password itself. A missing file is reported as "not logged
 in"; a file that exists but is corrupt is reported as such, naming the bad
-field. When the server answers a command's request with HTTP 401, because it no
+field. When the refresh a command starts with gets HTTP 401 from the server,
-longer accepts the saved session's token, the command prints one line,
+because it no longer accepts the saved session's token, the command prints one
-`quak: the saved session is no longer valid; run "quak login"`, with no stack
+line, `quak: the saved session is no longer valid; run "quak login"`, with no
-trace. All three exit with status 3, which means the user must run `quak login`
+stack trace. All three exit with status 3, which means the user must run
-again. `quak logout` is the exception: with no file it says there is no session
+`quak login` again. `quak logout` is the exception: with no file it says there
-and exits 0, and it handles a corrupt file or a failed server call as described
+is no session and exits 0, and it handles a corrupt file or a failed server call
-below. `quak backup` meets an expired session on the refresh that starts every
+as described below. `quak backup` meets an expired session on the refresh that
-run, before it touches any file. No command but `quak login` ever prompts.
+starts every run, before it touches any file. A session that stops working
+partway through a backup instead fails each remaining file into `failures.json`,
+so that run exits 1 and the next one stops at its refresh with status 3. No
+command but `quak login` ever prompts.
 
 `quak logout` ends the session on the server, so the token in `session.json`
 stops working even in a copy of the file, and then deletes the file. If the

test/cli/commands.test.ts

@@ -230,14 +230,24 @@ describe("session file", () => {
         expect(JSON.parse(readFileSync(path, "utf-8"))).toEqual(snapshot);
     });
 
-    it("a missing session exits 3 with 'Not logged in'", async () => {
+    it("a missing session exits 3 with 'Not logged in' from every command that needs one", async () => {
         const ctx = { ...context(), loadSession };
+        const dir = join(root, "backup");
         expect(await whoamiCommand(ctx)).toBe(3);
-        expect(stderr.text).toBe(
+        expect(await collectionsCommand(ctx, {})).toBe(3);
+        expect(await filesCommand(ctx, { collection: "1" })).toBe(3);
+        expect(await getCommand(ctx, "100", {})).toBe(3);
+        expect(await getThumbCommand(ctx, "100", {})).toBe(3);
+        expect(await backupMetadataCommand(ctx, dir, {})).toBe(3);
+        expect(await backupCommand(ctx, dir, {})).toBe(3);
+        expect(await listMissingThumbnailsCommand(ctx, {})).toBe(3);
+        expect(await fixMissingThumbnailsCommand(ctx, {})).toBe(3);
+        const notLoggedIn =
             `Not logged in. Run "quak login" first.\n` +
-                `Session file: ${join(ctx.sessionDir, "session.json")}\n`,
+            `Session file: ${join(ctx.sessionDir, "session.json")}\n`;
-        );
+        expect(stderr.text).toBe(notLoggedIn.repeat(9));
         expect(stdout.text).toBe("");
+        expect(existsSync(dir)).toBe(false);
     });
 
     it("a corrupt session exits 3 and says it is corrupt", async () => {