fix(fuse,core,cli): resume a session another process refreshed

`pdfs unlock` resumes the daemon's session and may refresh it. The
daemon then holds a spent refresh token, and since B202 a refusal of it
read as an expired session although the keyring held a live one.

Before calling a refused session expired, compare the keyring with what
this process last stored. When it holds a newer rotation or another
login, end the mount with `MountOutcome::ResumeStored` and mount again
from the keyring. A rotation another process already wrote counts as
this session's, so the daemon keeps writing its later ones (B203).

crates/pdfs-cli/src/main.rs

@@ -2193,6 +2193,9 @@ fn cmd_daemon(mountpoint: Option<PathBuf>) -> Result<()> {
                 tracing::info!("daemon stopping");
                 return Ok(());
             }
+            Ok(pdfs_fuse::MountOutcome::ResumeStored) => {
+                tracing::info!("resuming the session stored in the keyring");
+            }
             Ok(pdfs_fuse::MountOutcome::Unmounted) => {
                 tracing::warn!("mount ended externally; remounting in 2s");
                 pdfs_fuse::idle_sleep(std::time::Duration::from_secs(2));