refactor(ribbon): make StyleContext borrowed to avoid 8 clones per view

Replace the 8 owned clones in StyleContext construction (4 Vec<String>
+ 4 String) at ribbon/mod.rs:568 and :1059 with borrowed refs.
StyleContext is now StyleContext<'a> with &'a [String]/&'a str
(widgets.rs:313), RenderCtx holds &'a StyleContext<'a> (:633),
and call sites pass &self.x instead of .clone(). The view-local
borrow is valid for the duration of Ribbon::view() and the style
dropdown overlay.

TDD: RED style_context_tests failed E0308 (owned vs borrowed),
GREEN added lifetime and updated 4 type sites + 2 construction sites.

src/ui/ribbon/mod.rs

@@ -566,14 +566,14 @@ impl Ribbon {
             if let Some(module) = self.modules.get(effective_active) {
                 let groups = module.ribbon_groups();
                 let style_ctx = StyleContext {
-                    text_style_names: self.text_style_names.clone(),
-                    active_text_style: self.active_text_style.clone(),
-                    dim_style_names: self.dim_style_names.clone(),
-                    active_dim_style: self.active_dim_style.clone(),
-                    mleader_style_names: self.mleader_style_names.clone(),
-                    active_mleader_style: self.active_mleader_style.clone(),
-                    table_style_names: self.table_style_names.clone(),
-                    active_table_style: self.active_table_style.clone(),
+                    text_style_names: &self.text_style_names,
+                    active_text_style: &self.active_text_style,
+                    dim_style_names: &self.dim_style_names,
+                    active_dim_style: &self.active_dim_style,
+                    mleader_style_names: &self.mleader_style_names,
+                    active_mleader_style: &self.active_mleader_style,
+                    table_style_names: &self.table_style_names,
+                    active_table_style: &self.active_table_style,
                 };
 
                 // Adaptive tool area: panels sit on one row; when they don't all
@@ -1057,14 +1057,14 @@ impl Ribbon {
         let (style_key, manager_cmd) = found?;
 
         let ctx = StyleContext {
-            text_style_names: self.text_style_names.clone(),
-            active_text_style: self.active_text_style.clone(),
-            dim_style_names: self.dim_style_names.clone(),
-            active_dim_style: self.active_dim_style.clone(),
-            mleader_style_names: self.mleader_style_names.clone(),
-            active_mleader_style: self.active_mleader_style.clone(),
-            table_style_names: self.table_style_names.clone(),
-            active_table_style: self.active_table_style.clone(),
+            text_style_names: &self.text_style_names,
+            active_text_style: &self.active_text_style,
+            dim_style_names: &self.dim_style_names,
+            active_dim_style: &self.active_dim_style,
+            mleader_style_names: &self.mleader_style_names,
+            active_mleader_style: &self.active_mleader_style,
+            table_style_names: &self.table_style_names,
+            active_table_style: &self.active_table_style,
         };
         let active = ctx.active_for(style_key).to_string();
 
@@ -1298,7 +1298,7 @@ fn render_group<'a>(
     active_color: AcadColor,
     active_linetype: &'a str,
     active_lineweight: LineWeight,
-    style_ctx: &StyleContext,
+    style_ctx: &StyleContext<'_>,
 ) -> Element<'a, Message> {
     let mut items_row: Vec<Element<Message>> = Vec::new();
     let mut small_buf: Vec<Element<Message>> = Vec::new();
@@ -1419,7 +1419,7 @@ fn collapse_button<'a>(
     active_color: AcadColor,
     active_linetype: &'a str,
     active_lineweight: LineWeight,
-    style_ctx: &StyleContext,
+    style_ctx: &StyleContext<'_>,
     // When set, this is the TIGHT step (reached once even the all-collapsed row
     // overflows): the whole panel becomes a single non-running button — the first
     // tool's icon + a ▾ that opens the tools flyout. Nothing runs directly here.