test(cli): the IIF warning count ignores P8's audit notice; the harness asks the platform where the root is

GitHub's check on 880278ea: `cpa_package_holds_the_year_and_its_evidence`
counts the IIF transliteration warnings, and P8's "No counted audit
stands behind this package" notice (a warning while the books hold no
audit run) made four into five; the count now excludes it.

The portable macOS job, now that the harness prints the server's log:
"there is no books' private folder yet: run `wanderbooks setup`
first". `Home::root()` spelled out `.local/share/wanderbooks`, the
Linux data folder; `setup --home` on macOS makes the root under
`Library/Application Support`. The harness asks `default_root` now,
the same answer on every OS.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HS8WZziDnyxunC23MUxrLp

crates/ledger-cli/tests/common/mod.rs

@@ -78,8 +78,12 @@ impl Home {
         }
     }
 
+    /// The root `setup --home` made: the platform's data folder under the
+    /// home (`.local/share` on Linux, `Library/Application Support` on
+    /// macOS), never a Linux path spelled out (the portable macOS job
+    /// found the server refusing a root that was never set up).
     pub fn root(&self) -> PathBuf {
-        self.dir.path().join(".local/share/wanderbooks")
+        ledger_store::root::default_root(self.dir.path())
     }
 
     pub fn run(&self) -> PathBuf {