fix: Windows reads of lock files, update paths cfg(unix), merge main again (P11c)

spec_vault swept every file under a book, lock files included; on Windows
a held LockFileEx lock is mandatory and the read failed. The locks are
already dedicated files (never data), so the test skips *.lock. Merged
main (P13 step 6, the macOS server.log assert, P11a's AppImage identity):
host.rs keeps main's five-field identity on Unix and size/last-write on
Windows; the update poll and set_program_version are Unix-only.

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

@@ -205,7 +205,13 @@ impl Server {
         BufReader::new(child.stdout.take().unwrap())
             .read_line(&mut line)
             .unwrap();
-        assert_eq!(line, "ready\n", "the server didn't say ready");
+        if line != "ready\n" {
+            // Say why (the portable jobs run this on macOS and Windows,
+            // where the only evidence is what the server wrote).
+            let said =
+                std::fs::read_to_string(home.dir.path().join("server.log")).unwrap_or_default();
+            panic!("the server didn't say ready (got {line:?}); its log:\n{said}");
+        }
         Self { child }
     }