style(docs): replace em dashes with hyphens for consistency

docs/TOOL_CALLS.md

@@ -141,7 +141,7 @@ Each patch object contains:
 }
 ```
 
-> **Note:** Multi-patch operations are atomic—all patches are validated before any are applied. If any patch fails, no changes are made.
+> **Note:** Multi-patch operations are atomic - all patches are validated before any are applied. If any patch fails, no changes are made.
 
 ---
 

docs/USER_GUIDE.md

@@ -258,7 +258,7 @@ On X11-based desktops (e.g., Openbox, i3, Fluxbox), window capture has the follo
 
 *   **Current workspace only**: The window picker only shows windows on your active workspace. Windows on other virtual desktops cannot be captured because X11 does not render off-screen windows.
 *   **Window must be visible**: The target window must be visible and not fully obscured by another window. If a window is covered, the capture may return a black image. **Click the window to bring it to the front before capturing.**
-*   **Compositors help**: If you run a compositor such as `picom` or `compton`, these limitations are largely eliminated — compositors maintain off-screen buffers for all windows, enabling capture of obscured or unfocused windows.
+*   **Compositors help**: If you run a compositor such as `picom` or `compton`, these limitations are largely eliminated - compositors maintain off-screen buffers for all windows, enabling capture of obscured or unfocused windows.
 
 These limitations do not apply to **Wayland** desktops (GNOME, KDE Plasma 6) or **macOS**, which use compositing by default.