fix(tui): trim whitespace-only selection chrome

- clamp selection highlight to real row content so blank drag margins do not render or copy
- keep successful copy actions quiet while preserving usage and failure feedback

ui-tui/src/app/slash/commands/core.ts

@@ -269,7 +269,6 @@ export const coreCommands: SlashCommand[] = [
       }
 
       writeOsc52Clipboard(target.text)
-      sys(`copied ${target.text.length} chars`)
     }
   },
 

ui-tui/src/app/useInputHandlers.ts

@@ -30,11 +30,7 @@ export function useInputHandlers(ctx: InputHandlerContext): InputHandlerResult {
   const copySelection = () => {
     // ink's copySelection() already calls setClipboard() which handles
     // pbcopy (macOS), wl-copy/xclip (Linux), tmux, and OSC 52 fallback.
-    const text = terminal.selection.copySelection()
-
-    if (text) {
-      actions.sys(`copied ${text.length} chars`)
-    }
+    terminal.selection.copySelection()
   }
 
   const clearSelection = () => {