Dock: move app-side dock code into app::dock, trim tests, drop icon tooltip

- The dock's state handling and drawing move out of update/dialog.rs and
  view/mod.rs into src/app/dock/ (update.rs, view.rs, tests.rs). The
  overlay view_main stacked over the workspace (floating pallets, + menu,
  drag preview, pointer capture) becomes one `dock_overlay` call. Code is
  moved, not changed.
- Strip icons no longer show the pallet name on hover.
- Tests trimmed where they overlapped: the top / bottom half drops are
  one test, the two hover tests are one, and the in-group icon reorder,
  raise-float, empty floating title bar and slot-span tests are dropped
  (each is covered by another test).

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_013RyGiMXcsf9HTKfqDxaQGt

src/ui/dock.rs

@@ -1412,22 +1412,6 @@ mod tests {
         assert_eq!((f.x, f.w), (DOCK_MIN_W - 350.0, 350.0));
     }
 
-    #[test]
-    fn raise_float_moves_it_to_the_front() {
-        let mut state = DockState::default();
-        for id in [PanelId::Count, PanelId::Browser] {
-            state.float(FloatPanel {
-                id,
-                x: 0.0,
-                y: 0.0,
-                w: 300.0,
-                h: 300.0,
-            });
-        }
-        state.raise_float(PanelId::Count);
-        assert_eq!(state.floating.last().map(|f| f.id), Some(PanelId::Count));
-    }
-
     #[test]
     fn every_panel_has_its_own_icon() {
         let ids = PanelId::ALL;
@@ -1439,25 +1423,4 @@ mod tests {
         }
     }
 
-    #[test]
-    fn floating_title_bar_replaces_the_horizontal_one() {
-        let floating = Chrome {
-            floating: true,
-            ..Default::default()
-        };
-        let bar: Element<'_, Message> = title_bar(PanelId::Count, "Count".into(), floating);
-        assert_eq!(
-            bar.as_widget().size(),
-            iced::Size::new(Length::Fixed(0.0), Length::Fixed(0.0))
-        );
-    }
-
-    #[test]
-    fn slot_spans_follow_weights() {
-        assert_eq!(
-            slot_spans(&[1.0, 3.0], 400.0),
-            vec![(0.0, 100.0), (100.0, 400.0)]
-        );
-        assert!(slot_spans(&[], 400.0).is_empty());
-    }
 }