W75: Keymap tests for F3/Shift-F3 View/ViewRaw bindings

Add 2 keymap unit tests:
- f3_is_view_and_shift_f3_is_view_raw: verifies the MC-parity
  binding (F3=View, Shift-F3=ViewRaw)
- appearance_has_nonempty_name: verifies the new Cmd::Appearance
  variant has a description string

Tests: 1431 pass (was 1429), zero warnings.

local/recipes/tui/tlc/source/src/keymap/mod.rs

@@ -664,4 +664,20 @@ mod tests {
             assert!(!cmd.name().is_empty(), "{cmd:?} ({key:?}) has empty name");
         }
     }
+
+    #[test]
+    fn f3_is_view_and_shift_f3_is_view_raw() {
+        let km = default_keymap();
+        assert_eq!(km.lookup(F3), Some(Cmd::View));
+        let shift_f3 = Key {
+            code: F3.code,
+            mods: crate::key::Modifiers::SHIFT,
+        };
+        assert_eq!(km.lookup(shift_f3), Some(Cmd::ViewRaw));
+    }
+
+    #[test]
+    fn appearance_has_nonempty_name() {
+        assert!(!Cmd::Appearance.name().is_empty());
+    }
 }