fix: get_categories locale filter and list-type filter (v0.4.9)

Bug 1: all 171 category locale variants were returned; now filtered by
locale parameter (default "de") → 13 German categories for shopping lists.

Bug 2: TODO lists returned 171 shopping categories because
sortingIndexByTaskList contains ALL list IDs regardless of type.
Fix: look up list's taskListType via taskgettasklists, then match against
category's taskListType. TODO lists (type=TODOS) return empty list since
all API categories are SHOPPING_LIST type.

sortingIndexByTaskList is explicitly documented as unreliable for type
filtering in both code comments and SPEC.md.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/mcp_familywall/server.py

@@ -337,23 +337,40 @@ def get_tasks(list_id: str, only_open: bool = True):
 
 
 @mcp.tool()
-def get_categories(list_id: str) -> str:
+def get_categories(list_id: str, locale: str = "de") -> str:
     """Return the task categories available for a list as JSON.
 
-    Categories are loaded from taskcategorysync (part of accgetallfamily) and
-    filtered to those assigned to the given list via sortingIndexByTaskList.
-    Shopping lists have predefined system categories (aisles); TODO lists
-    typically only carry a single default system category.
+    Only shopping lists (taskListType=SHOPPING_LIST) have categories. TODO
+    lists return an empty list. Categories are filtered by locale so only
+    the language-appropriate names are returned (default: German).
 
     Note: the parameter name for assigning a category when creating or
     updating a task is not yet verified via FW_DEBUG=1. See SPEC.md.
 
     Args:
         list_id: List ID from get_lists (e.g. ``taskList/23431854_29740942``).
+        locale: BCP-47 language code for category names (default ``"de"``).
+            Supported values seen in API: de, en, fr, es, it, nl, pt, sv,
+            ru, ko, ja.
 
     Returns:
-        JSON list of {id, name, emoji} objects ordered by sortingIndex.
+        JSON list of {id, name, emoji} objects ordered by sortingIndex,
+        or an empty list when the list type has no categories.
     """
+    # Resolve the list's taskListType from taskgettasklists so we can match
+    # only the categories that belong to the same list type.  Non-fatal: if
+    # the lookup fails we skip the type filter and return all locale matches.
+    list_type: str | None = None
+    try:
+        list_data = _authenticated_call("taskgettasklists", {})
+        raw_lists = list_data.get("a00", {}).get("r", {}).get("r", []) or []
+        for lst in raw_lists:
+            if lst.get("metaId") == list_id:
+                list_type = lst.get("taskListType")
+                break
+    except RuntimeError:
+        pass
+
     try:
         data = _accgetallfamily()
     except RuntimeError as exc:
@@ -370,18 +387,16 @@ def get_categories(list_id: str) -> str:
             indent=2,
         )
 
-    # Collect categories assigned to this list, ordered by their sorting index.
+    # Filter by locale (exact match) and taskListType (when known).
+    # sortingIndexByTaskList is NOT used for filtering: all categories are
+    # assigned to all lists regardless of type, making it an unreliable signal.
     matched: list[tuple[int, dict[str, Any]]] = []
-    seen: set[str] = set()
     for cat in raw_cats:
-        sorting = cat.get("sortingIndexByTaskList") or {}
-        if list_id not in sorting:
+        if cat.get("locale") != locale:
             continue
-        cat_id: str = cat.get("metaId", "")
-        if cat_id in seen:
+        if list_type is not None and cat.get("taskListType") != list_type:
             continue
-        seen.add(cat_id)
-        sort_val = int(sorting.get(list_id, cat.get("initialSortingIndex", 0)) or 0)
+        sort_val = int(cat.get("initialSortingIndex") or 0)
         matched.append((sort_val, cat))
 
     matched.sort(key=lambda t: t[0])