feat(tags): Implement full MCP support for Tagged Task Lists and update-task append mode

.changeset/free-pants-rescue.md

@@ -0,0 +1,18 @@
+---
+"task-master-ai": minor
+---
+
+Enhance update-task with --append flag for timestamped task updates
+
+Adds the `--append` flag to `update-task` command, enabling it to behave like `update-subtask` with timestamped information appending. This provides more flexible task updating options:
+
+**CLI Enhancement:**
+- `task-master update-task --id=5 --prompt="New info"` - Full task update (existing behavior)
+- `task-master update-task --id=5 --append --prompt="Progress update"` - Append timestamped info to task details
+
+**Full MCP Integration:**
+- MCP tool `update_task` now supports `append` parameter
+- Seamless integration with Cursor and other MCP clients
+- Consistent behavior between CLI and MCP interfaces
+
+Instead of requiring separate subtask creation for progress tracking, you can now append timestamped information directly to parent tasks while preserving the option for comprehensive task updates.

.changeset/six-cups-see.md

@@ -25,6 +25,16 @@ The new tagged system fundamentally changes how tasks are organized:
 - `task-master rename-tag <old> <new>` - Rename tags with automatic current tag reference updates
 - `task-master copy-tag <source> <target> [options]` - Duplicate tag contexts for experimentation
 
+**🤖 Full MCP Integration for Tag Management:**
+
+Task Master's multi-context capabilities are now fully exposed through the MCP server, enabling powerful agentic workflows:
+- **`list_tags`**: List all available tag contexts.
+- **`add_tag`**: Programmatically create new tags.
+- **`delete_tag`**: Remove tag contexts.
+- **`use_tag`**: Switch the agent's active task context.
+- **`rename_tag`**: Rename existing tags.
+- **`copy_tag`**: Duplicate entire task contexts for experimentation.
+
 **Tag Creation Options:**
 - `--copy-from-current` - Copy tasks from currently active tag
 - `--copy-from=<tag>` - Copy tasks from specific tag