Toolbar: a click on the tear-off bar floats the group, window.floatTools, strips in workspaces (review of #437)

- A click on a flyout's tear-off bar, or the release of the long press
  that opened it over the bar, tears the flyout off too, as in
  Illustrator; dragging it still does.
- window.floatTools {tool, floating?} floats or puts back the group
  holding a tool, for the control channel and MCP's invoke_menu.
- Floating strips are part of user workspaces; the built-in ones float
  none, so Reset puts them back.
- Loaded preferences keep one strip per group, of known tools.
- No per-frame clone of the strips or copy of the active tool's id.
- docs/control-protocol.md, ROADMAP, Float Tool Group translations.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/ui-egui/src/workspaces.rs

@@ -7,7 +7,7 @@ use std::sync::atomic::Ordering;
 use serde::{Deserialize, Serialize};
 use serde_json::{Value, json};
 
-use crate::state::{Dialog, DockTab, UiState};
+use crate::state::{Dialog, DockTab, FloatingFlyout, UiState};
 use crate::theme::Tokens;
 use crate::{VectorcraftApp, widgets};
 
@@ -27,6 +27,8 @@ pub struct Workspace {
     pub dock_collapsed: bool,
     pub open_panel: Option<String>,
     pub status_bar: bool,
+    /// Tool groups torn off the toolbar into floating strips (built-in workspaces: none).
+    pub floating_flyouts: Vec<FloatingFlyout>,
 }
 
 impl Default for Workspace {
@@ -120,6 +122,7 @@ pub fn capture(ui: &UiState, name: &str) -> Workspace {
         dock_collapsed: ui.dock_collapsed,
         open_panel: ui.open_panel.clone(),
         status_bar: ui.status_bar,
+        floating_flyouts: ui.floating_flyouts.clone(),
     }
 }
 
@@ -136,6 +139,7 @@ pub fn apply(ui: &mut UiState, w: &Workspace) {
     ui.dock_collapsed = w.dock_collapsed;
     ui.open_panel = w.open_panel.clone();
     ui.status_bar = w.status_bar;
+    ui.floating_flyouts = w.floating_flyouts.clone();
     ui.flyout = None;
     ui.workspace = w.name.clone();
 }