core/views: Add footer text with hotkey hint for copying traceback.

tests/ui_tools/test_popups.py

@@ -1428,7 +1428,7 @@ def test_stream_info_content__sections(self) -> None:
         "stream_email_present, expected_copy_text",
         [
             (False, "< Stream email is unavailable >"),
-            (True, "Press 'c' to copy Stream email address"),
+            (True, "Press [c] to copy Stream email address"),
         ],
     )
     def test_stream_info_content__email_copy_text(

zulipterminal/core.py

@@ -674,6 +674,7 @@ def no_prompt_exit_handler(self, signum: int, frame: Any) -> None:
         self.deregister_client()
 
     def prompting_exit_handler(self, signum: int, frame: Any) -> None:
+        self.view.set_footer_text()
         question = urwid.Text(
             ("bold", " Please confirm that you wish to exit Zulip-Terminal "),
             "center",
@@ -721,6 +722,16 @@ def _raise_exception(self, *args: Any, **kwargs: Any) -> Literal[True]:
                 full_traceback = "".join(traceback.format_exception(*exc))
                 self.show_exception_popup(message, traceback=full_traceback, width=80)
                 self._exception_info = None
+
+                if full_traceback != "":
+                    text = [
+                        "An exception occurred: ",
+                        "Press [c] to copy traceback to clipboard.",
+                    ]
+                else:
+                    text = ["Press [Esc] to exit popup."]
+
+                self.view.set_footer_text(text, "task:error")
         return True  # If don't raise, retain pipe
 
     def main(self) -> None:

zulipterminal/ui_tools/views.py

@@ -1091,6 +1091,8 @@ def __init__(
     def keypress(self, size: urwid_Size, key: str) -> str:
         if is_command_key("COPY_TRACEBACK", key):
             self.controller.copy_to_clipboard(self.traceback, "Traceback")
+        if is_command_key("GO_BACK", key):
+            self.controller.view.set_footer_text()
         return super().keypress(size, key)