feat: add Task CRUD tools – create, update, toggle, delete (v0.4.0)

Implements four new MCP write tools via taskcreate2, taskupdate2,
taskmark, and metadelete endpoints. Confirmation prompts noted in
docstrings for destructive/mutating operations. Body parameters
documented in SPEC.md as pending verification via FW_DEBUG=1.

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

src/mcp_familywall/server.py

@@ -1,4 +1,4 @@
-"""MCP server for Family Wall — read-only tools for circles, lists and tasks."""
+"""MCP server for Family Wall — tools for circles, lists, tasks (read + write)."""
 
 from __future__ import annotations
 
@@ -299,6 +299,176 @@ def get_activities(limit: int = 20):
     return json.dumps(result, ensure_ascii=False, indent=2)
 
 
+# ---------------------------------------------------------------------------
+# Helper: authenticated single call
+# ---------------------------------------------------------------------------
+
+
+def _authenticated_call(endpoint: str, params: dict[str, Any]) -> dict[str, Any]:
+    """Login, call *endpoint* with *params*, logout, and return the response body.
+
+    Args:
+        endpoint: Family Wall API endpoint name.
+        params: Form parameters to send.
+
+    Raises:
+        RuntimeError: On credential or API errors.
+    """
+    try:
+        email, password = get_credentials()
+    except RuntimeError as exc:
+        raise RuntimeError(str(exc)) from exc
+
+    try:
+        with FamilyWallClient() as client:
+            client.login(email, password)
+            data = client.call(endpoint, params)
+            client.logout()
+        return data
+    except FamilyWallError as exc:
+        raise RuntimeError(f"Family Wall API error: {exc}") from exc
+    except Exception as exc:
+        raise RuntimeError(f"Connection error: {exc}") from exc
+
+
+# ---------------------------------------------------------------------------
+# Tool: create_task
+# ---------------------------------------------------------------------------
+
+
+@mcp.tool()
+def create_task(list_id: str, text: str, description: str | None = None) -> str:
+    """Create a new task in the given list.
+
+    IMPORTANT: Ask the user for confirmation before calling this tool.
+
+    Args:
+        list_id: Target list ID from get_lists (e.g. ``taskList/123_456``).
+        text: Task title / main text.
+        description: Optional longer description.
+
+    Returns:
+        JSON with the new task's metaId on success, or an error message.
+    """
+    params: dict[str, Any] = {"taskListId": list_id, "text": text}
+    if description:
+        params["description"] = description
+
+    try:
+        data = _authenticated_call("taskcreate2", params)
+    except RuntimeError as exc:
+        return f"Error: {exc}"
+
+    # Try to extract the new task's metaId from the response.
+    try:
+        meta_id = data["a00"]["r"]["r"]["metaId"]
+    except (KeyError, TypeError):
+        # Return raw response so the caller can inspect the actual structure.
+        return json.dumps(
+            {"warning": "Unexpected taskcreate2 response structure", "raw": data},
+            ensure_ascii=False,
+            indent=2,
+        )
+
+    return json.dumps({"created": True, "id": meta_id}, ensure_ascii=False, indent=2)
+
+
+# ---------------------------------------------------------------------------
+# Tool: update_task
+# ---------------------------------------------------------------------------
+
+
+@mcp.tool()
+def update_task(task_id: str, text: str | None = None, description: str | None = None) -> str:
+    """Update the text and/or description of an existing task.
+
+    IMPORTANT: Ask the user for confirmation before calling this tool.
+    At least one of *text* or *description* must be provided.
+
+    Args:
+        task_id: Task metaId from get_tasks.
+        text: New title text (omit to leave unchanged).
+        description: New description (omit to leave unchanged).
+
+    Returns:
+        JSON success indicator or an error message.
+    """
+    if text is None and description is None:
+        return "Error: At least one of 'text' or 'description' must be provided."
+
+    params: dict[str, Any] = {"metaId": task_id}
+    if text is not None:
+        params["text"] = text
+    if description is not None:
+        params["description"] = description
+
+    try:
+        _authenticated_call("taskupdate2", params)
+    except RuntimeError as exc:
+        return f"Error: {exc}"
+
+    # A response without 'ex'/'un' keys is treated as success by fw_client.
+    return json.dumps({"updated": True, "id": task_id}, ensure_ascii=False, indent=2)
+
+
+# ---------------------------------------------------------------------------
+# Tool: toggle_task
+# ---------------------------------------------------------------------------
+
+
+@mcp.tool()
+def toggle_task(task_id: str, complete: bool) -> str:
+    """Mark a task as complete or incomplete.
+
+    Args:
+        task_id: Task metaId from get_tasks.
+        complete: ``True`` to mark done, ``False`` to reopen.
+
+    Returns:
+        JSON success indicator or an error message.
+    """
+    params: dict[str, Any] = {
+        "metaId": task_id,
+        "complete": "true" if complete else "false",
+    }
+
+    try:
+        _authenticated_call("taskmark", params)
+    except RuntimeError as exc:
+        return f"Error: {exc}"
+
+    return json.dumps(
+        {"toggled": True, "id": task_id, "complete": complete},
+        ensure_ascii=False,
+        indent=2,
+    )
+
+
+# ---------------------------------------------------------------------------
+# Tool: delete_task
+# ---------------------------------------------------------------------------
+
+
+@mcp.tool()
+def delete_task(task_id: str) -> str:
+    """Permanently delete a task. This action cannot be undone.
+
+    IMPORTANT: Ask the user for confirmation before calling this tool.
+
+    Args:
+        task_id: Task metaId from get_tasks.
+
+    Returns:
+        JSON success indicator or an error message.
+    """
+    try:
+        _authenticated_call("metadelete", {"metaId": task_id})
+    except RuntimeError as exc:
+        return f"Error: {exc}"
+
+    return json.dumps({"deleted": True, "id": task_id}, ensure_ascii=False, indent=2)
+
+
 # ---------------------------------------------------------------------------
 # Factory
 # ---------------------------------------------------------------------------