refactor: clamp canvas pointer movement, prioritize local pan offset, and remove debug logs

hcie-iced-app/crates/hcie-iced-gui/src/app.rs

@@ -9495,7 +9495,6 @@ impl HcieIcedApp {
         );
 
         // Toolbox — 36px strip (single column) or 72px (2 columns) on the left edge
-        log::info!("[view] sidebar_expanded={}", self.sidebar_expanded);
         let toolbox = crate::sidebar::view(
             &self.tool_state,
             &self.fg_color,

hcie-iced-app/crates/hcie-iced-gui/src/canvas/shader_canvas.rs

@@ -1016,13 +1016,12 @@ impl shader::Program<Message> for CanvasShaderProgram {
 
                         // Left mouse drag (drawing)
                         if state.left_pressed {
-                            if let (Some(cx), Some(cy)) = (canvas_x, canvas_y) {
-                                return (
-                                    iced::event::Status::Captured,
-                                    Some(Message::CanvasPointerMoved { x: cx, y: cy }),
-                                );
-                            }
-                            return (iced::event::Status::Captured, Some(pane_size_msg));
+                            let cx = canvas_x.unwrap_or(0.0).clamp(0.0, self.engine_w as f32);
+                            let cy = canvas_y.unwrap_or(0.0).clamp(0.0, self.engine_h as f32);
+                            return (
+                                iced::event::Status::Captured,
+                                Some(Message::CanvasPointerMoved { x: cx, y: cy }),
+                            );
                         }
 
                         // Middle mouse drag (panning)
@@ -1261,7 +1260,7 @@ impl shader::Program<Message> for CanvasShaderProgram {
             canvas_w: self.engine_w,
             canvas_h: self.engine_h,
             zoom: self.zoom,
-            pan_offset: self.pan_offset,
+            pan_offset: state.local_pan_offset.unwrap_or(self.pan_offset),
             texture_update: self.texture_update.clone(),
             composite_pixels: self.composite_pixels.clone(),
             full_upload: self.full_upload,

hcie-iced-app/crates/hcie-iced-gui/src/sidebar/mod.rs

@@ -168,11 +168,6 @@ pub fn view<'a>(
     expanded: bool,
 ) -> Element<'a, Message> {
     let sidebar_width = if expanded { 72 } else { 36 };
-    log::info!(
-        "[sidebar] expanded={} open_subtool_slot={:?}",
-        expanded,
-        open_subtool_slot
-    );
 
     // Tool buttons — single column or 2-column grid depending on expanded state
     let mut tool_list = column![].spacing(1);