fix: land watch serve client override fix and changelog (#411) (thanks @chrysb)

CHANGELOG.md

@@ -15,6 +15,7 @@
 - Timezone: embed the IANA timezone database so Windows builds can resolve calendar timezones correctly. (#388) — thanks @visionik.
 - Gmail: add a fetch delay in `watch serve` so History API reads don't race message indexing. (#397) — thanks @salmonumbrella.
 - Gmail: allow Workspace-managed send-as aliases with empty verification status in `send` and `drafts create`. (#407) — thanks @salmonumbrella.
+- Gmail: preserve the selected `--client` during `watch serve` push handling instead of falling back to the default client. (#411) — thanks @chrysb.
 - Secrets: respect empty `GOG_KEYRING_PASSWORD` (treat set-to-empty as intentional; avoids headless prompts). (#269) — thanks @zerone0x.
 - Calendar: reject ambiguous calendar-name selectors for `calendar events` instead of guessing. (#131) — thanks @salmonumbrella.
 - Gmail: `drafts update --quote` now picks a non-draft, non-self message from thread fallback (or errors clearly), avoiding self-quote loops and wrong reply headers. (#394) — thanks @salmonumbrella.

internal/cmd/gmail_watch_serve_test.go

@@ -351,7 +351,7 @@ func TestGmailWatchServeCmd_PreservesClientOverrideForRequestContexts(t *testing
 		if client := authclient.ClientOverrideFromContext(ctx); client != "personal" {
 			t.Fatalf("expected client override personal, got %q", client)
 		}
-		return nil, nil
+		return &gmail.Service{}, nil
 	}
 
 	u, err := ui.New(ui.Options{Stdout: io.Discard, Stderr: io.Discard, Color: "never"})