some webUI fixes

python_app/gui/controllers/app_window_config/live_processing_mixin.py

@@ -298,11 +298,23 @@ class AppWindowLiveProcessingMixin:
         ``_on_processing_live_settings_changed`` handler — one writer, one redraw —
         so the browser and the desktop never desync and ``processing_live.json`` has
         exactly one author. The per-widget change signals are neutralized by a
-        suppression flag so the final handler runs once instead of dozens of times;
-        a history command keeps its own server-managed sequence-bump path.
+        suppression flag so the final handler runs once instead of dozens of times.
+
+        A destructive history command is not a settings edit: it routes to the very
+        same handler the desktop's "Clear History" / "Remove Last" button uses, so the
+        browser drains the ring readers, empties the runtime histories, clears the
+        render caches and the processor's replay state, and redraws — rather than only
+        nudging the processor while the on-screen history stays put.
         """
         try:
             history_command = str(fields.get("history_command", "none"))
+            if history_command == "clear_all":
+                self._clear_all_runtime_history()
+                return
+            if history_command == "remove_last":
+                self._remove_last_runtime_history()
+                return
+
             settings = {
                 name: value
                 for name, value in fields.items()
@@ -310,10 +322,7 @@ class AppWindowLiveProcessingMixin:
             }
             # Log only field names (not values) so remote edits are traceable
             # without recording arbitrary client-supplied payloads.
-            self._log_debug(
-                f"Applying web live settings: fields={sorted(settings)}, "
-                f"history_command={history_command}."
-            )
+            self._log_debug(f"Applying web live settings: fields={sorted(settings)}.")
             self._suppress_live_settings_handler = True
             try:
                 # processor_mode first: dual-sourced gpr_* fields route to the gpr or
@@ -324,9 +333,6 @@ class AppWindowLiveProcessingMixin:
                     _set_web_live_field(self, name, value)
             finally:
                 self._suppress_live_settings_handler = False
-
-            if history_command in {"clear_all", "remove_last"}:
-                self._write_live_processing_config(history_command=history_command, bump_history_seq=True)
             self._on_processing_live_settings_changed()
         except Exception as exc:  # noqa: BLE001
             self._show_exception("Failed to apply web live settings", exc)

python_app/gui/controllers/app_window_config/profile_io_mixin.py

@@ -172,32 +172,39 @@ class AppWindowConfigProfileIOMixin:
         except Exception as exc:  # noqa: BLE001
             self._show_exception("Failed to save config profile", exc)
 
-    def _load_config_from_dialog(self) -> None:
-        """Load full GUI profile from a user-selected JSON file."""
+    def _ensure_ready_to_load_config(self) -> bool:
+        """Return whether a config load may proceed, reporting the blocker if not.
+
+        Loading rebuilds every widget and resizes history, so it is refused while a
+        capture sequence or the pipeline is active — the operator must stop first.
+        Shared by the desktop dialog and the web loader so both honor the same rule.
+        """
         if self._capture_session is not None:
             self._show_error(
                 "Cannot load config during active capture sequence",
                 details=self._capture_state_details(),
             )
-            return
+            return False
         if self._supervisor.is_running():
             self._show_error(
                 "Stop all pipeline processes before loading a config profile",
                 details=self._process_state_details(),
             )
-            return
+            return False
+        return True
 
-        selected_path, _selected_filter = QFileDialog.getOpenFileName(
-            self,
-            "Load Config Profile",
-            str(self._active_profile_path),
-            "JSON Files (*.json);;All Files (*)",
-        )
-        if not selected_path:
-            return
+    def _load_config_from_path(self, config_path: Path) -> None:
+        """Load a full GUI profile from ``config_path`` and apply it to the UI.
 
+        This is the single authoritative load path: the desktop "Load Config" dialog
+        and the web config picker both funnel here, differing only in how they obtain
+        the path. The pipeline is left untouched; live settings reach a running
+        data_processor immediately while stable settings stage for the next Start.
+        """
+        if not self._ensure_ready_to_load_config():
+            return
         try:
-            normalized_path = self._normalize_profile_path(Path(selected_path))
+            normalized_path = self._normalize_profile_path(config_path)
             profile = GuiProfileModel.load_from_path(normalized_path)
             processor_running = self._supervisor.is_processor_running()
             self._apply_loaded_profile(profile, normalized_path)
@@ -217,6 +224,20 @@ class AppWindowConfigProfileIOMixin:
         except Exception as exc:  # noqa: BLE001
             self._show_exception("Failed to load config profile", exc)
 
+    def _load_config_from_dialog(self) -> None:
+        """Load a full GUI profile from a user-selected JSON file (desktop button)."""
+        if not self._ensure_ready_to_load_config():
+            return
+        selected_path, _selected_filter = QFileDialog.getOpenFileName(
+            self,
+            "Load Config Profile",
+            str(self._active_profile_path),
+            "JSON Files (*.json);;All Files (*)",
+        )
+        if not selected_path:
+            return
+        self._load_config_from_path(Path(selected_path))
+
     def _apply_loaded_profile(self, profile: GuiProfileModel, profile_path: Path) -> None:
         """Apply an already parsed profile to GUI state without restarting the pipeline.