feat(mcp): Add tagInfo to responses and integrate ContextGatherer

Enhances the MCP server to include 'tagInfo' (currentTag, availableTags) in all tool responses, providing better client-side context.

- Introduces a new 'ContextGatherer' utility to standardize the collection of file, task, and project context for AI-powered commands. This refactors several task-manager modules ('expand-task', 'research', 'update-task', etc.) to use the new utility.

- Fixes an issue in 'get-task' and 'get-tasks' MCP tools where the 'projectRoot' was not being passed correctly, preventing tag information from being included in their responses.

- Adds subtask '103.17' to track the implementation of the task template importing feature.

- Updates documentation ('.cursor/rules', 'docs/') to align with the new tagged task system and context gatherer logic.

.taskmaster/tasks/task_098.txt

@@ -219,7 +219,7 @@ Create a new core function (e.g., research.js) in scripts/modules/task-manager/
 The research command now provides the same polished user experience as other AI-powered commands in the system.
 </info added on 2025-05-25T06:29:01.194Z>
 
-## 5. Direct Function Implementation [pending]
+## 5. Direct Function Implementation [done]
 ### Dependencies: 98.4
 ### Description: Create the MCP direct function wrapper in mcp-server/src/core/direct-functions/ following the add-task pattern
 ### Details:
@@ -233,7 +233,7 @@ Create a new direct function (e.g., research.js) in mcp-server/src/core/direct-f
 - Handles telemetry data propagation
 - Export and register in task-master-core.js
 
-## 6. MCP Tool Implementation [pending]
+## 6. MCP Tool Implementation [done]
 ### Dependencies: 98.5
 ### Description: Create the MCP tool in mcp-server/src/tools/ following the add-task tool pattern
 ### Details: