Run cargo fmt on the unit code and drop a quantity box's invalid mark when its line is removed

The new CI runs cargo fmt --check. QuantityInput also reported its validity only when it changed, so removing a line
whose quantity box held bad text left that box counted as invalid and blocked issuing; it now reports valid when it
unmounts, and no longer writes a ref during render.

Claude-Session: https://claude.ai/code/session_01PZypiWDfMkDTeEPeXjRhW5

src-tauri/src/integrations/erpnext/config.rs

@@ -67,7 +67,10 @@ impl NamingMode {
 /// Voiced line unit to ERPNext UOM. Whole-number UOMs such as "Nos" reject fractional quantities,
 /// which is why hours, minutes, kilometres and the like map to their own UOMs (see `units::KNOWN`).
 pub fn default_uom_map() -> BTreeMap<String, String> {
-    crate::units::KNOWN.iter().map(|(id, uom)| (id.to_string(), uom.to_string())).collect()
+    crate::units::KNOWN
+        .iter()
+        .map(|(id, uom)| (id.to_string(), uom.to_string()))
+        .collect()
 }
 
 /// Everything stored for the integration, secret included. Backend-only.