Fix retry crash for unregistered remotes in the Sessions popup

Opening a window whose target was removed from the registry (its tab
stays open by design) and failing landed in the action menu with a
"重试连接" row that indexed self.entries directly and raised KeyError,
killing the popup with a traceback.

Only offer the retry action for registered targets, degrade a stale
retry row to a message, and keep the popup alive when a handler raises
anything unexpected instead of dying with a traceback.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

herdr_hub/selector.py

@@ -616,7 +616,13 @@ class SessionSelector:
             except curses.error:
                 continue
 
-            outcome = self._handle_key(key, filtered)
+            try:
+                outcome = self._handle_key(key, filtered)
+            except Exception as error:  # noqa: BLE001 - keep the popup alive
+                # A handler bug must not replace the popup with a traceback.
+                self._show_main()
+                self.message = f"内部错误：{type(error).__name__}: {error}"
+                continue
             if isinstance(outcome, SelectorResult) or outcome is False:
                 return outcome if isinstance(outcome, SelectorResult) else None
 
@@ -797,7 +803,12 @@ class SessionSelector:
         elif source.kind == "retry":
             rows.append(_action_row(source, "retry", "action-retry", "重试连接"))
 
-        if source.kind != "retry" and source.error is not None and source.target is not None:
+        if (
+            source.kind != "retry"
+            and source.error is not None
+            and source.target is not None
+            and source.target in self.entries
+        ):
             rows.append(_action_row(source, "retry", "action-retry", "重试连接"))
 
         if source.kind == "window" and source.endpoint_key is not None:
@@ -1008,8 +1019,15 @@ class SessionSelector:
             self._show_actions(row)
         elif row.kind in {"retry", "action-retry"}:
             assert row.target is not None
+            entry = self.entries.get(row.target)
+            if entry is None:
+                # The window's target was removed from the registry while its
+                # tab stayed open; there is nothing to re-query.
+                self._show_main()
+                self.message = f"{row.target} 未登记为远端，无法重试；可通过“添加远端”重新登记"
+                return None
             self.results.pop(row.target, None)
-            self.pool.enqueue(self.entries[row.target])
+            self.pool.enqueue(entry)
             self._show_main()
             self.message = f"正在重试 {row.target}"
         elif row.kind == "action-new":
@@ -1122,7 +1140,7 @@ class SessionSelector:
             return result
         try:
             self.activate_handler(result)
-        except (OSError, RuntimeError, ValueError) as error:
+        except Exception as error:  # noqa: BLE001 - shown inside the popup
             detail = str(error).strip() or "未知错误"
             self.message = f"打开失败：{detail}"
             if row is not None:
@@ -1144,7 +1162,7 @@ class SessionSelector:
         if self.rename_handler is not None:
             try:
                 self.rename_handler(self.input_key, normalized)
-            except (OSError, RuntimeError, ValueError) as error:
+            except Exception as error:  # noqa: BLE001 - shown inside the popup
                 self.message = str(error)
                 return None
 
@@ -1280,7 +1298,7 @@ class SessionSelector:
         self.pending_action = None
         try:
             outcome = future.result()
-        except (OSError, RuntimeError, ValueError) as error:
+        except Exception as error:  # noqa: BLE001 - shown inside the popup
             self._show_main()
             entry = self.entries.get(action.target)
             if entry is not None:
@@ -1368,7 +1386,7 @@ class SessionSelector:
         )
         try:
             self.windows = list(self.close_window_handler(window_id))
-        except (OSError, RuntimeError, ValueError) as error:
+        except Exception as error:  # noqa: BLE001 - shown inside the popup
             self.message = f"关闭 Tab 失败：{error}"
             return
         self._show_main()