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.

scripts/modules/config-manager.js

@@ -669,6 +669,16 @@ function isConfigFilePresent(explicitRoot = null) {
 	return fs.existsSync(configPath);
 }
 
+/**
+ * Gets the user ID from the configuration.
+ * @param {string|null} explicitRoot - Optional explicit path to the project root.
+ * @returns {string|null} The user ID or null if not found.
+ */
+function getUserId(explicitRoot = null) {
+	const config = getConfig(explicitRoot);
+	return config?.global?.userId || null;
+}
+
 /**
  * Gets a list of all provider names defined in the MODEL_MAP.
  * @returns {string[]} An array of provider names.
@@ -714,7 +724,7 @@ export {
 	getProjectName,
 	getOllamaBaseUrl,
 	getParametersForRole,
-
+	getUserId,
 	// API Key Checkers (still relevant)
 	isApiKeySet,
 	getMcpApiKeyStatus,