feat(telemetry): Implement AI usage telemetry pattern and apply to add-task

This commit introduces a standardized pattern for capturing and propagating AI usage telemetry (cost, tokens, model used) across the Task Master stack and applies it to the 'add-task' functionality.

Key changes include:

- **Telemetry Pattern Definition:**
  - Added  defining the integration pattern for core logic, direct functions, MCP tools, and CLI commands.
  - Updated related rules (, ,
 Usage: mcp [OPTIONS] COMMAND [ARGS]...

 MCP development tools

╭─ Options ──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╮
│ --help          Show this message and exit.                                                                                                │
╰────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯
╭─ Commands ─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╮
│ version   Show the MCP version.                                                                                                            │
│ dev       Run a MCP server with the MCP Inspector.                                                                                         │
│ run       Run a MCP server.                                                                                                                │
│ install   Install a MCP server in the Claude desktop app.                                                                                  │
╰────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯, , ) to reference the new telemetry rule.

- **Core Telemetry Implementation ():**
  - Refactored the unified AI service to generate and return a  object alongside the main AI result.
  - Fixed an MCP server startup crash by removing redundant local loading of  and instead using the  imported from  for cost calculations.
  - Added  to the  object.

- ** Integration:**
  - Modified  (core) to receive  from the AI service, return it, and call the new UI display function for CLI output.
  - Updated  to receive  from the core function and include it in the  payload of its response.
  - Ensured  (MCP tool) correctly passes the  through via .
  - Updated  to correctly pass context (, ) to the core  function and rely on it for CLI telemetry display.

- **UI Enhancement:**
  - Added  function to  to show telemetry details in the CLI.

- **Project Management:**
  - Added subtasks 77.6 through 77.12 to track the rollout of this telemetry pattern to other AI-powered commands (, , , , , , ).

This establishes the foundation for tracking AI usage across the application.

.cursor/rules/new_features.mdc

@@ -3,7 +3,6 @@ description: Guidelines for integrating new features into the Task Master CLI
 globs: scripts/modules/*.js
 alwaysApply: false
 ---
-
 # Task Master Feature Integration Guidelines
 
 ## Feature Placement Decision Process
@@ -196,6 +195,8 @@ The standard pattern for adding a feature follows this workflow:
   - ✅ **DO**: If an MCP tool fails with vague errors (e.g., JSON parsing issues like `Unexpected token ... is not valid JSON`), **try running the equivalent CLI command directly in the terminal** (e.g., `task-master expand --all`). CLI output often provides much more specific error messages (like missing function definitions or stack traces from the core logic) that pinpoint the root cause.
   - ❌ **DON'T**: Rely solely on MCP logs if the error is unclear; use the CLI as a complementary debugging tool for core logic issues.
 
+- **Telemetry Integration**: Ensure AI calls correctly handle and propagate `telemetryData` as described in [`telemetry.mdc`](mdc:.cursor/rules/telemetry.mdc).
+
 ```javascript
 // 1. CORE LOGIC: Add function to appropriate module (example in task-manager.js)
 /**