feat(rename): complete searchSpace to workspace transition across frontend and backend

- Introduced a comprehensive specification for renaming `searchSpace` to `workspace` in `surfsense_web` and `surfsense_desktop`, ensuring all TypeScript identifiers, React props, and local data structures are updated.
- Implemented migration shims for persisted local state to prevent data loss during the transition.
- Updated observability metrics and IPC channels to reflect the new naming convention.
- Removed legacy `active-search-space` module and replaced it with `active-workspace` to maintain consistency.
- Ensured no behavioral changes or data loss for users during the renaming process.

surfsense_backend/app/observability/metrics.py

@@ -543,7 +543,7 @@ def record_kb_search_duration(
     _record(
         _kb_search_duration(),
         duration_ms,
-        {"search_space.id": workspace_id, "search.surface": surface},
+        {"workspace.id": workspace_id, "search.surface": surface},
     )
 
 

surfsense_backend/app/observability/otel.py

@@ -261,7 +261,7 @@ def kb_search_span(
     """Span around knowledge-base search routines."""
     attrs: dict[str, Any] = {}
     if workspace_id is not None:
-        attrs["search_space.id"] = int(workspace_id)
+        attrs["workspace.id"] = int(workspace_id)
     if query_chars is not None:
         attrs["query.chars"] = int(query_chars)
     if extra:
@@ -303,7 +303,7 @@ def chat_request_span(
     if chat_id is not None:
         attrs["chat.id"] = int(chat_id)
     if workspace_id is not None:
-        attrs["search_space.id"] = int(workspace_id)
+        attrs["workspace.id"] = int(workspace_id)
     if flow:
         attrs["chat.flow"] = flow
     if request_id: