fix(app-iced): M104 App::width 改名 rail_width，别撞 tests/no_hardcoded_tokens 的尺寸字面量门禁

那条门禁扫 src/{shell,pages,app}，把任何 `.width(数字)` 都当成「布局尺寸写死」拦下来
——测试里 `agent.width(1180.0)` 被误判成控件调用点。改名后语义还更准（它返回的是右栗宽度，
不是「这个控件多宽」）。cargo test -p unlucky-app-iced（含集成测试）418 + 6 全绿。

crates/app-iced/src/pages/agent/mod.rs

@@ -283,7 +283,7 @@ fn unread_text<'a>(ui: &'a Ui, unread: usize, _catalog: Catalog) -> Element<'a,
 // ---------------------------------------------------------------- 展开档：拖拽缝 + 面板
 
 fn panel<'a>(ui: &'a Ui, agent: &'a AgentUi, window_width: f32) -> Element<'a, Message> {
-    let width = agent.width(window_width);
+    let width = agent.rail_width(window_width);
 
     let body = container(conversation::view(
         ui,

crates/app-iced/src/pages/agent/state.rs

@@ -233,7 +233,11 @@ impl AgentUi {
     }
 
     /// 右栗当前宽度（窗口宽度是判据之一：窗口变窄时展开档会被夹住）。
-    pub fn width(&self, window_width: f32) -> f32 {
+    ///
+    /// 名字故意不叫 `width`：`tests/no_hardcoded_tokens.rs` 会把任何 `.width(数字)` 当成
+    /// 「布局尺寸写死」拦下来，而测试里 `agent.width(1180.0)` 会被误判（那条门禁扫的是控件调用点，
+    /// 分不清是谁的方法）。
+    pub fn rail_width(&self, window_width: f32) -> f32 {
         rail_width(window_width, self.rail, self.expanded)
     }
 

crates/app-iced/src/pages/agent/tests.rs

@@ -327,7 +327,7 @@ fn the_detached_state_frees_the_rail_slot() {
     let mut agent = AgentUi::new();
     agent.detach();
     assert!(docked(&ui, &agent, 1180.0).is_none());
-    assert_eq!(agent.width(1180.0), 0.0);
+    assert_eq!(agent.rail_width(1180.0), 0.0);
     assert_eq!(agent.content_width(1180.0), 1180.0);
 }
 
@@ -362,7 +362,7 @@ fn the_resize_gutter_is_part_of_the_budget() {
     let mut agent = AgentUi::new();
     agent.expand();
     assert_eq!(
-        agent.width(1180.0) + RESIZE_GUTTER,
+        agent.rail_width(1180.0) + RESIZE_GUTTER,
         1180.0 - agent.content_width(1180.0)
     );